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  1. Trailer Coupler Locks
  2. Master Lock
  3. Fits 1-7/8 Inch Ball
  4. Fits 2 Inch Ball
  5. Fits 2-5/16 Inch Ball
  6. Surround Lock
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

Retail:$45.99
Our Price: $28.65
You Save: 38%
Trailer Coupler Locks
Shipping Weight: 1.73 lbs
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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. Great 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 1-800-940-8924 for expert service.
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  • Reviews (807)
  • Q & A (0)
  • Photos

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
  • 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 Satisfaction Score:


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   (807 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:

Great locks!! I feel a lot better leaving all three of my trailers at home with these locks on my trailers! Definitely recommend!



by:

I have multiple trailers with different ball hitch sizes and Master Lock fits all of them well.



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:

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.

Smithsonite

5/26/2023

Working great! No issues whatsoever. I keep the moving parts, including the key tumbler well lubed with white lithium grease, so this one is going to last.



by:

This is my second order from etrailers.com and the experience was rough due to the postal service on my first order but the staff was amazing at helping me work to find the shipment and even called my local post office. I was sold on this company and now my church uses them for all our trailer needs. They are extremely good at communications and updated me every step of the way including who worked with my package and even contacting me to ask if I wanted an alternative part that would have been here sooner. I love working with this company!



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!?!

Douglas

12/16/2020

Still working great, no complaints here.



by:

Got this coupler lock for my boat trailer, easy to put on and take off.
So far it is working as expected, as do all the products I have purchased so far from etrailer.



by:

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

Etrailer Expert

Sierra K.

7/22/2022

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 would fit better.



by:

Part looks great right out of the package... I have a 2 5/16" Ball coupler and the lock works perfectly on it... I'm thinking the lock is not coming off of the trailer without the key... Couldn't be happier with the lock...



by:

Must be working... my trailer hasnt been stolen. I use every time in storage and at campgrounds. Easy to use.. Adjusts to fit snugly to coupler.. Doesnt bind up when installing or removing.. design much easier to use than some others.



by:

Universals lock, great for many applica tions



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 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:

So far the product looks, feels and works great. Shipping was very fast.



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:

Universal lock



by:

Appears as though each of the coupler locks will perform well. Both fit the 2” and the 2 5/16” couplers sufficiently to protect the trailers from thieves.



by:

I need to return it . It doesn't fit on my trailer.

Etrailer Expert

Jenny N.

7/24/2023

I will have our Customer Service team contact you about returning the lock. In the meantime, I want to find a lock that will work for you. Can you tell me how it is not fitting? What type of coupler do you have?



by:

Simple design, reliable and common master lock key. 1 squirt of oil once per year keeps it excellent while living outside in daily coastal marine layer (salty dew) passes my needs test



by:

I installed this trailer lock as soon as I purchased it. All I have done is spray the lock with WD40 a couple times and the lock has protected my favorite boat with NO problems at all.



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:

Nice lock. It’s nice that there is nothing to really cut on it. Latches on nice and strong. Easy to use. You could even use a default latch lock with it. Hope it holds up as good as it looks. Will review again after awhile.



by:

Nice tool, I like that it will adjust easily for different depths so it will fit more than one size trailer tongue. It pulls in snug and with a couple firm smacks with a 2 pound hammer is still works just fine.



by:

Easy to find the correct size, price point is great. My go to site for auto accessories.



by:

More security for my trailer while looking good.


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807
Show More Reviews

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

  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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    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 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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  • 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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  • 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 Adjustable Coupler
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  • Coupler Lock and Trailer Hitch Receiver Lock for 2-1/2 Inch Hitch
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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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  • Replacement Key for Master Lock ML389DAT Trailer Coupler Lock
    To obtain a replacement key, you'll need to know the 4 digit code that was stamped on the key. You'd use part # MLK1. On the product page, near the 'add to cart' button, you'd need to type in the 4 digit key number.
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  • Replacement 3398 Keys for Master Lock Trailer Coupler Lock
    To get replacement keys for the Master Lock Trailer Coupler Lock # ML389DAT you'll need the Replacement Key for MasterLock Coupler Locks # MLK1. Just type in the key number prior to placing your order and we'll get the correct keys sent out to you!
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  • How to Get a Replacement Key for a Master Lock 389DAT Trailer Coupler Lock
    For a replacement key for your Master Lock Trailer Coupler Lock # ML389DAT, you will use the Replacement Key for MasterLock Coupler Locks # MLK1. You just need to put your key number in the key number box on the Replacement Key for MasterLock Coupler Locks # MLK1 page.
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  • How To Obtain Replacement Keys for MasterLock Trailer Coupler Locks
    Yes, we do offer replacement keys for MasterLock Trailer Coupler Locks. In order to obtain this you'd simply need the Replacement Key for MasterLock Coupler Locks part # MLK1. There is a spot on that page where you will be prompted to enter your key number as it appears on the face of the lock core and or key. This is different than the model number of the coupler lock itself. If there is no key number present there would be no way to identify this key and unfortunately that means a new...
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Info for this part was:

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