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Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers

Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers

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Trailer Coupler Locks
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Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers Universal Application Lock ML389DAT
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Keep your trailer safe from towaway theft with this universal coupler lock. Its tough frame fits in and around most 1-7/8", 2", and 2-5/16" ball couplers; and it has a bright red color and heavy-duty construction to deter theft. Lowest Prices for the best trailer coupler locks from Master Lock. Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers part number ML389DAT can be ordered online at etrailer.com or call 1-636-306-4830 for expert service.
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  • Reviews (726)
  • Q & A (0)
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  • Why etrailer?

Master Lock Trailer Coupler Locks

  • Fits 1-7/8 Inch Ball
  • Fits 2 Inch Ball
  • Fits 2-5/16 Inch Ball
  • Surround Lock
  • Keyed Unique
  • Master Lock
  • Universal Application Lock

Keep your trailer safe from towaway theft with this universal coupler lock. Its tough frame fits in and around most 1-7/8", 2", and 2-5/16" ball couplers; and it has a bright red color and heavy-duty construction to deter theft.


Features:

  • Heavy-duty coupler lock deters trailer theft by preventing hookup
  • Large size and heavy weight defend against attempts to break or shatter lock
  • Wafer-tumbler lock mechanism resists picking and prying
  • 1-Piece housing slides to fit tightly around your coupler
  • Powder coat resists rust and corrosion
    • Red color provides a visible theft deterrent
  • Keyway cover protects lock from moisture and debris
  • 2 Keys included


Specs:

  • Application: most 1-7/8", 2" and 2-5/16" couplers
    • Fits standard lip, rolled lip, straight lip, surge brake, hammer blow, and UFP couplers
  • Limited lifetime warranty


Note: This product cannot be keyed alike.


Instructions for Locking the Trailer Coupler

  1. Insert key and turn clockwise to unlock.
  2. Pull the ball out from the lock body as far as it will go.
  3. Insert the ball of the lock into your coupler's ball socket.
  4. Push the lock body in so that it surrounds your coupler.
  5. Turn key counterclockwise to lock.


389DAT Master Lock Universal Trailer Coupler Lock - 1-7/8", 2" and 2-5/16"

Item # ML389DAT






Customer Reviews

Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers - ML389DAT

Average Customer Rating:  4.8 out of 5 stars   (726 Customer Reviews)

Keep your trailer safe from towaway theft with this universal coupler lock. Its tough frame fits in and around most 1-7/8", 2", and 2-5/16" ball couplers; and it has a bright red color and heavy-duty construction to deter theft.

by:

Doesn't fit on a 2 5/16 equipment trailer. Made for small, lawn-mower trailers.


Comments
I am sorry this coupler lock did not work for you. I think the hump on top of your coupler is the culprit. I think item # C48CR
Curt Tri-Ball Trailer Coupler Lock for 1-7/8", 2" and 2-5/16" Ball Couplers
$21.15
would fit better.
-- Etrailer Expert Sierra K - 07/22/2022


by:

If ever I need anything and I mean anything that has to do with towing or trailers or racks they have I save gas easy-peezy


Comments
grrrreat!
Thurman R - 03/29/2022


by:

Glad to see they went back to the original design. I have a chrome colored one I bought 13 years ago that is this style, still working. About 10 years ago I bought a 2nd one for my other trailer, and it was nothing like this one - cheap plastic everywhere, could easily be defeated. Backed into it once, and all the plastic broke off revealing just how flimsy it was. Was pleasantly surprised to see Master Lock went back to this much better design. I expect to get over 10 years out of this one.




by:

Recently bought a boat and the trailer did not have any way to lock the tongue that I could see. After seeing that my stepson had a trailer with this style lock on it and seeing that it would be virtually impossible to pry it off I did some research. I have purchased from etrailer in the past and trust them to only sell the best. I ordered it and received it in a timely manner. It fits perfectly and I now feel my trailer and boat are secure. Who would doubt the Master Lock brand anyway!?!


Comments
Still working great, no complaints here.
Douglas - 12/16/2020


by:

I feel much better about parking my trailer on the street with this lock on the hitch. Not only does it lock up the hitch securely but the bright red color signals to prospective thieves that this trailer cannot be towed.
It is easy to attach and easy to remove. Also very compact so it can be stored easily. The shipping time was less than I expected. etrailer.com is my goto supplier for my trailer accessories.




by:

This is a terrific design since unlike padlocks, can't easily be cut with bolt cutters. I like the bright red color which tells a thief there is a lock to deal with from a distance. I think someone who wants your trailer can probably defeat any system you use, so the goal is to make it tough as possible and I think this lock does that.




by:

LOOK OK, BUT WORRY PEOPLE WILL USE BIG HAMMER TO HIT AND DESTROY THE LOCK
to prevent the gentleman or not prevent the real theft to steel the trailer
at least get some protection from my mind ,




by:

I don’t worry about someone driving off with my trailer now since installing the master lock. Paid for 2 day shipping and it arrived the second day. This is my third or fourth time buying from etrailer, and they are top notch




by:

Works well I like the fact that it`s easy to connect, fits 1-7/8" ball up to 2-5/16" and protects my trailer peace of mind




by:

This is just the anti-theft deterrent device we have been looking for. We have an Excavation business and keep a lot of expensive tools and equipment in a 6x12 trailer. We can sleep at night knowing our trailer will still be there in the morning. This thing is very easy to put on and take off.




by:

Great product. Master Lock brand and quality. Very secure and provides me with peace of mind that it’s a huge deterrent to would-be boat thieves.




by:

It fits the 2 5/16" ball the of all the other ones I tried.




by:

We purchased this lock based on a recommendation from a friend, as well as the written reviews. It is heavy and substantial, and I am relieved to have an extra layer of protection for our trailer while camping in area's without security. Etrailer comes though yet again.




by:

Works perfectly. I now own 2 of these, for use on two different hitch types. Bright color is also a deterrent, I think.




by:

It's a great product. It looks good on the trailer, and you can see it from very afar. And there is no way to saw it off, break it apart, or something like that. The construction is basically rounded, and there is nowhere you can find a starting point to place a saw or breakaway device on it. I have also bought different lock from Reese, and it looks wimpy, and easy to take it apart, or saw it off as some reviews have suggested. It's also easy to put it on and take it off. Just love the product. Here I attach some pictures in the campgrounds, etc.




by:

After years of no worry trailer and boat five-fingered discount from bad guys interested in stealing my first unhitched boat using a trailer coupler lock much like this one I now have confidence my new boat will be similarly safe using the bright red Master Coupler Lock. I like the red color which makes it obvious the bad guys need to move on to find another victim.




by:

Have not used the product yet but it looks very solid and the service from etrailer was excellent like always and the price was right.




by:

I received the Master Lock Trailer Coupler Lock that I ordered. It was delivered in just a few days just a it was supposed to. It is exactly what I was looking for. It will help detour anyone from stealing my trailer ! I am extremely happy with the lock and etrailer ! I think this is a great company with great pricing on there products ! I will recommend them to everybody and will be ordering with them again real soon ! It was an easy and excellent experience. Great customer service too ! Thanks etrailer !




by:

I have no reason to believe it will fail or is not a quality product. My gut feeling is the style with the ball over the top might be better




by:

We just put it on, so can't speak for how it will hold up. It was nice and light, and very easy to put on. We got the 16' one and it fits great on our Bigfoot 9-6.




by:

your product is a great buy however the delivery sucks. the delivery guy dropped off my purchase in the driveway next to the mailbox, instead of on the porch, making it easy for a passerby to lift it.




by:

This lock was chosen by me for medium security of our 20' boat. I was installed easily and will keep most who want to try to steal something like our boat away. If they really wanted to, a sledge would destroy this. Where there's a will there's a way.
For our 31' trailer, I opted for another model. That would take a lot more beating to 'maybe' get off the hitch. It also costs about 8 times as much though...


Comments
After one year, taking it off. Our boat is in use again after 1 year, going to Lake Mead. It has held up great, easy to open, and kept thieves away...
Jerome M - 08/17/2018



by:

Purchased two of these to replace pin style coupler locks. Decent coupler lock, will probably provide a fair amount of deterrence. However, it does not snuggly fit into either of the trailers I outfitted with these locks. There is a fair amount of wiggle even when adjusted completely. Still looking for a better coupler lock option...




by:

Very easy to slide on and off. Good snug fit. Design makes it harder to cut off than a bent bar design.




by:

Very good product that works well when trailer is unattended.


Comments
Heavy duty and reliable!
Dwayne - 11/04/2021

25
726
Show More Reviews

See what our Experts say about this Master Lock Trailer Coupler Locks



  • Material of the Master Lock Coupler Lock part # ML389DAT
    The Master Lock Coupler Lock part # ML389DAT that you referenced is made of steel. It is basically the red powder coated version of the older Master Lock 379ATPY.
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  • Coupler Lock for Vintage Coupler on 1949 Airstream
    Thank you so much for the photos and for your 2" coupler I recommend the Master Lock Trailer Coupler Lock # ML389DAT. This is a heavy-duty and easy to use coupler lock; you only need to put the ball of the lock into the coupler's ball socket, push the body of the lock in and turn the key. I have added links to a pair of video reviews for you to take a look at as well.
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  • Recommendation For A 2 Inch Trailer Coupler Lock For A 2017 CM Dakota Two Horse Trailer
    Based on your information, your 2017 CM Dakota 2 Horse Trailer is bumper pulled. The Master Lock Trailer Coupler Lock, Item # ML389DAT, works with 1-7/8 inch, 2 inch, and 2-5/26 inch ball couplers. It fits most standard couplers and should fit your 2 inch Bulldog coupler. If this will not work for you, let me know and I will recommend other options.
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  • Will Master Lock Coupler Lock # ML389DAT Fit Big Tex 70DM-18 Car Hauler
    The Master Lock Trailer Coupler Lock # ML389DAT will work well on your Big Tex 70DM 18 car trailer. I looked up pictures of the trailer and found that it has a collar lock style coupler which we know this lock works great with. I attached a picture of this lock used on a similar coupler for you to check out as well.
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  • Can Master Lock Trailer Coupler Lock be Pried Off
    Realistically, the Master Lock Trailer Coupler Lock # ML389DAT won't be pried off; even if there's enough room to fit a crowbar, getting it fully wedged in so that enough leverage can be applied to the lock to break it off just isn't going to happen. Theoretically, any lock can be busted with enough force but the odds of your trailer getting stolen with this lock on it are extraordinarily slim compared to not having the Master Lock on.
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  • Construction of Master Lock # ML389DAT Coupler Lock
    The Master Lock # ML389DAT trailer coupler lock is constructed of powder coated steel. If you click the provided link, you can see a product demonstration video. As you can see by its rating, the folks who've purchased the lock are happy with it.
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  • Would the Master Lock Trailer Coupler Lock # ML389DAT Fit an Interstate Cargo Trailer
    I looked up some pictures of the couplers that are on Interstate cargo trailers and the Master Lock Trailer Coupler Lock # ML389DAT that you referenced would fit the couplers and would work well. I attached a review video for this lock for you to check out as well.
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  • Construction of Master Lock # ML389DAT Trailer Coupler Lock
    The Master Lock # ML389DAT is constructed of steel, as opposed to pot metal. Pot metal is an alloy made of non-ferrous metals with low melting points like zinc, lead, copper, tin and aluminum. The lock wouldn't shatter or crack if struck by a hammer, unless extraordinary means like liquid nitrogen were used on the lock first. Although just about any lock can be defeated by a determined criminal if they are motivated enough and have enough time, the rugged construction of the # ML389DAT...
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  • What Size Hitch Balls Does Masterlock Coupler Lock part # ML389DAT Fit
    The Masterlock Coupler Lock part # ML389DAT fits the three most common hitch ball sizes, 1-7/8 inch, 2 inch, and 2-5/16 inch. I attached a review video for this coupler lock for you to check out as well.
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  • Does Master Lock Trailer Coupler Lock # ML389DAT Come with a Cover for the Key Hole
    The Master Lock Trailer Coupler Lock # ML389DAT does not come with a cover for the key hole. The covers are a bit of a double edged sword though. On one hand they keep out dirt and debris, but on the other they trap moisture in the lock core which can cause corrosion to build.
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  • BestTrailer Coupler Lock for R-Pod Trailer
    The best trailer coupler lock for your 2015 R-Pod R178 - or other R-Pods with a 1-7/8", 2" or 2-5/16" ball coupler for that matter - is the Master Lock Trailer Coupler Lock # ML389DAT. The reason this is the best lock is because it offers the most protection from removal due to its unique design which ensures it won't be able to be pried off, cut off, or hammered off. It is also a bright red so any would-be thieves will know right away you have a trailer that isn't going to be worth their...
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  • Troubleshooting MasterLock Coupler Lock Where Key Seems Stuck
    Try shooting some WD40 with a straw into the key slot of the Master Lock Trailer Coupler Lock # ML389DAT to see if you can get it to free up stuck tumblers. Most likely that will fix the issue but if not let me know!
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  • Trailer Coupler Lock to Replace One With no Key
    Replacement keys for trailer coupler locks from this manufacturer were once something that was offered, but because there was so much difficulty getting the correct key they are no longer available. That means the only option if you don't have a key is to cut off your current lock and replace it. The good news is you can get an outstanding coupler lock for a price that is very similar to getting a replacement key. I strongly recommend the Master Lock Trailer Coupler Lock # ML389DAT which...
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  • Troubleshooting Key That Wont Turn for Red Master Lock Trailer Coupler Lock
    If you are having trouble unlocking the Master Lock Trailer Coupler Lock # ML389DAT then I recommend using a spray lubricant like WD-40 to help loosen up any dirt or grime that may have gotten in the lock. Let the spray sit in the lock for a few minutes and then try operating it again. If this still doesn't fix the problem then you may need to have a locksmith take a look at it.
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  • Can Master Lock Coupler Lock be Ordered With Specific Key Number
    Locks, including the Master Lock Trailer Coupler Lock # ML389DAT cannot be ordered with specific key numbers, they do come with a random key. I have added a link to a video review for you as well of the Master Lock Trailer Coupler Lock # ML389DAT.
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  • Recommended Trailer Coupler Lock for Adjustable Coupler
    I'm not sure I'm completely understanding what you're looking for here, but I think you might be able to use the Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers # ML389DAT to keep your trailer secured. This lock can be used on your trailer's coupler when the trailer is not attached to keep it safe from theft and it will work on any coupler size to keep the trailer from being coupled and driven away. I've linked a video review of this lock, as well as our entire...
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  • Trailer Coupler Lock For Coupler Without Pin Hole
    We do have trailer coupler locks you can use, but if your coupler doesn't have a pin hole, there isn't a way to lock it while it's attached to your vehicle's hitch ball; it will need to be uncoupled for a lock to be put on. Once you do that, you can use a surround-style lock, with the best option being from Master Lock: - Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers # ML389DAT This is a heavy-duty lock that fits around all different styles of trailer coupler...
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  • Recommended Trailer Coupler Lock For Coupler For 2-5/16 Inch Hitch Ball
    We have a coupler lock that is going to fit perfectly on your straight tongue coupler that attaches to a 2-5/16 inch hitch ball, with the best option being from Master Lock: - Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers # ML389DAT This is a really heavy-duty lock that is going to provide the best possible security for your coupler. The lock surrounds the front of your coupler so it can't be cut off, and is bright red which is a clear signal that the coupler...
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  • Recommended Coupler and Latch Lock for Trailer Exposed to Heavy Snow and Ice During Winter
    I have a solution for you, but considering the weather conditions that you're going to be exposing the lock to, I don't think the Master Lock # 377DAT is the best choice since it's not made from stainless steel and the lock mechanism is exposed. Instead, I recommend using the Master Lock Coupler Lock for 1-7/8", 2", 2-5/16" Couplers # ML389DAT. This lock has a Keyway cover for superior protection from the moister and debri and a powder coat finish resists rust and corrosion. It's red color...
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  • Coupler Lock and Trailer Hitch Receiver Lock for 2-1/2 Inch Hitch
    There is not a lock set like the one you mentioned which has the coupler locks and works with a 2-1/2 inch trailer hitch, so you would need to the hitch receiver lock and coupler locks separately and have two sets of keys for the locks. What you would need are: - Master Lock Coupler for 1-7/8", 2", 2-5/16" Couplers # ML389DAT - Stainless Steel Trailer Hitch Lock for 2-1/2" Receivers by Master Lock # 1469DAT I have added links to video reviews of both parts for you to check out as well.
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  • Surround Coupler Lock for 1-7/8-Inch Ball Coupler
    Gorilla Guard Trailer Coupler Lock # 63228 fits 2-inch couplers but we do have this surround-type lock style made for a 1-7/8-inch coupler. You can see all such 1-7/8-inch coupler locks on the linked page, such as # ML389DAT which fits three coupler sizes.
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  • Coupler Lock for 2-5/16" Trailer Coupler Ball
    We do not have any type of database of parts lists on each year, make and model of trailer so while we cannot tell you what type of coupler you have on your 2005 Airstream there are universal applications that should work. I recommend checking out the Master Lock Trailer Coupler Lock # ML389DAT which will work on your Airstream if you have a standard lip, rolled lip, straight lip, surge brake, hammer blow or UFP couplers. If you take a look at the accompanying photo you can see how this...
    view full answer...
    Image 1 for
  • Key Replacement for ML389 DAT
    You would need the part # MLK1. On the product page you would then need to enter the key number you need and we will ship you out the correct key.
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  • Can Multiple Master Lock Trailer Coupler Locks ML389DAT Be Ordered With Same Key
    I do have options but the Master Lock Trailer Coupler Lock part # ML389DAT does not have a keyed-like option so even if you were to order multiple at the same time, they still would not come with the same key most likely. Therefore, it would not be possible to order a new lock that uses the same key as the one you already have. The etrailer Trailer Coupler Lock part # e98893 for example does have a keyed-alike option so you could order multiple at the same time with the same key. I have...
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