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Optronics 7-Way Round to 5-Way Flat Trailer Connector Adapter

Optronics 7-Way Round to 5-Way Flat Trailer Connector Adapter

Item # A75TB
Our Price: $24.51
Trailer Wiring
Shipping Weight: 0.23 lbs
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Convert your vehicle's 7-way round plug to a 5-way flat with this adapter. Simple plug-and-play installation with no hardwiring needed. Removes easily with built-in finger tabls. Great Prices for the best trailer wiring from Optronics. Optronics 7-Way Round to 5-Way Flat Trailer Connector Adapter part number A75TB can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (183)
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  • Videos (2)
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Optronics Trailer Wiring - A75TB

  • Wiring Adapters
  • Single-Function Adapter
  • 5 Flat
  • Plug Only
  • 7 Round - Blade
  • Optronics

Convert your vehicle's 7-way round plug to a 5-way flat with this adapter. Simple plug-and-play installation with no hardwiring needed. Removes easily with built-in finger tabls.


  • Adapter converts your 7-way round, trailer-end socket for use with a 5-way flat vehicle-end plug
    • 7-Way Round connector plugs into your 7-way on your truck
    • 5-Way flat connector plugs into the 5-way flat wiring harness on your trailer
  • Curved finger tabs allow you to easily disconnect the adapter
  • 3-Year warranty

A75TB Optronics 7-Way Round to 5-Way Flat Trailer Connector Adapter

Alternate part number: A-75TB

California residents: click here

Video of Optronics 7-Way Round to 5-Way Flat Trailer Connector Adapter

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Optronics 7 Pole to 5 Pole Flat Adapter Review

Randy: Hey guys, it's Randy here at Today we're going to be taking a look at an adapter plug. We get questions a lot about how people can convert a working 7-Pole on the back of their vehicle to work with a 4-Pole or 5-Pole trailer. That can have a lot of needs, either a trailering in its own. Maybe you've got a cargo carrier that has lights on it. Maybe you just got a little hitch cover that you want to illuminate at night, if it's a plug-in type.

This can really help take care of all of those needs.Basically this is going to provide us either a 4-Pole connection or a 5-Pole connection. The 4-Pole connection is going to offer your ground, it's going to have running lights, left turn signal and brake, right turn signal and brake, and the 5th Pole is for a reverse signal. That's going to be really good for marine trailer applications, when we need to lockout our surge coupler so we can back our trailer up. Or, also, if you plan on adding lights to your trailer. Maybe you're in a dark area and you can't see where you're backing your trailer into.

Throwing a couple lights on the back and wiring it so that signal through your Pigtail. Every time you hit reverse on your vehicle, lights will come on the back of the trailer and give you a good way to look around.Now, all in all this has a good, solid feel to it. It's not as heavy as what I felt out of some of the other 4- and 5-Pole adapters here, and it is a split case design. You can see it has that line that goes around, they're screwed together. Some of these are going to be molded.

I think the moldeds are a little bit heavier. They seem to be a little bit more rugged, overall. I like this adapter. I think it's going to work out fairly well. The part that fits into your 7-Pole is going to be brass.

It doesn't have a nickel coating on it. That can lead to a little bit of corrosion issues, but we recommend with all adapters that you use dielectric grease. This is going to give us a barrier and prevent moisture from getting in there. Without moisture, we don't have to worry about that dirt settling in there and causing corrosion down the road. So that's kind of a give or take with me. I'm going to grease anything I use, so I really won't have to worry about it.If you have a shrouded 4-Pole connector, meaning that your ends don't stick out like what our 4-Pole connector do here. It's got more of a black plastic wrap that goes around it. You'll have to trim the side of it as we fit these together. Let me show you here. With that 5-Pole sticking out there, as we stick that on the side of that cover, it is going to interfere. So you'd have to trim that side out. When removing it, ler me put this all the way in. As we remove it, the insert in here tends to move a little bit. You can kind of see how that moves.Now as far as customer reviews you, people really like this. They haven't had any issues that causing any kind of a problem. I like that it's got a nice handle on there. The one thing I think this lacks that we see on some that are very comparable to this one, is going be a tester. Going to be a few red lights that'll come on and indicate to you if you've got a problem, your trailer lights aren't working. It can verify for you that your truck's lights are. So you know your problem's on the trailer side, you basically eliminate half of the problem in the equation.As far as the installation goes, going to be just like a 7-Pole plug. We've got our tab on the top here. That needs to go behind the tab on the door, right in there. Then you'll bring your 4- or 5-Pole in, and that's simply going to plug in. At that point, you've got the lighting and the power heading back to your trailer, so you should be in good shape.Now as far as if I would own this particular adapter versus some of the other ones out there, I'd have to say that I think I'd go with a different one. I'd go with one that had a little bit more option to it, kind of like the Reese here. This is product number 78118. Basically, it's going to be a little bit larger. Both of them are easy to install, but I like the fact that this one gives me a 4-Pole and a 5-Pole option. So regardless of the type of plug I'm using, it's going to go in there without modification. And it does have the LEDs in there, that are going to tell me if my truck's working, if I have a problem. So, all in all, while I think this is a good adapter and it's going to work out in a lot of situations, I think I'd own the Reese before I'd own this one.

Customer Satisfaction Score:

Customer Reviews

Optronics 7-Way Round to 5-Way Flat Trailer Connector Adapter - A75TB

Average Customer Rating:  4.9 out of 5 stars   (183 Customer Reviews)

Convert your vehicle's 7-way round plug to a 5-way flat with this adapter. Simple plug-and-play installation with no hardwiring needed. Removes easily with built-in finger tabls.


The whole staff at etrailer bent over backwards to make sure I was satisfied with the installation of brakes on my trailer. Have made several purchases from them always satisfied with parts and service. Special credit to Jamie great to deal with. Answered all my questions and was very knowledgeable.


Excellent product options with decent prices. Fast and dependable delivery. Would definitely buy from E-Trailer again when the need arises.


Great products, great information on the web site, fast delivery
I will definitely use etrailer in the future


converter was eady to use


etrailer continues to have great product selection and knowledgeable staff to ensure my needs are met. My boat trailer has a 5 flat plug with the 5th wire unused as I do not have trailer brakes. I had been using an 7-pole to 4-flat adapter and all my light functions worked. However, I was not happy that the spring loaded door did not fully lock in the adapter in place as it partially hit the 5-flat trailer plug. By using the proper adapter (7-pole to 5-flat), the spring loaded door fully locks the adapter in place to ensure it will not fall out when driving down the road. The product was shipped and received very quickly. etrailer will continue to be at the top of my list for such purchases.

Bill G.


1 year later, the adapter continues to work well... no issues at all.


etrailer is great. The site is easy to shop and navigate,thay had exactly what I was looking for at a very reasonable price.And as a bonus the adapter I ordered arrived faster than expected.The 7pole to 5pole flat adapter that I ordered works as it should, no more locking up of the brakes on my boat trailer when I am in reverse. I will be placing another order very soon.Thank you etrailer


Etrailer always have what I need at a good price and ships out fast.


Works as expected. Thanks !


This converter does exactly what I needed it to do ---- convert my 5 pin flat connecter on my boat trailer to the 7 pin connector on my new truck. It's keyed so even I can't insert it wrong! Perfect product for my need!

Mark G.


Its great, does exactly what I need. I dont haul the boat much, just to launch at start of year and pull out at end. But the adapter is perfect.


Fits my vehicle perfectively and is a breeze to connect. One year later after several times towing my trailer, the adapter it is still going strong. Still looks brand new.No complaints. I do disconnect it and store it inside my 2015 Surburban when not in use.



The trailer lights connect easily with this adapter. Still looks brand new and works great.


7 to five is a great change up. not needing a four and a five becuase the five is also a four.


Great product


Worked for me, I needed a five pin for the electric solenoid on the brake system for a boat trailer. Worked like a charm



Still in use all is working well


Great product at a great price. Fits perfect. Even has a protrusion that the cover of the truck plug leans against so the adapter cant be pulled out of the plug on my 2013 F150.

John T.


No complaints. It does what I need it to do. Need one? Buy it here at


Purchased trailer adapter 7 blade connecter to inline 5 for my 2005 Ram 1500, product arrived in a few days, quality is very good, price with shipping was cheaper than other sources....

Roger C.


Product still working very well.....


Super easy, inexpensive. I was planning to add a 5 flat wiring harness for my boat, then I saw this and it works great.



Inexpensive and solid. Worked just right. A year later still working without any issues.


I switched over my trailer wiring from a 4 way to a 5 way and got this adapter for my vehicle connection. Never had an issue after a year of use and I love this. It lets you know if your wiring and lights are working. I definitely recommend this.


This is a real must have if you're a Ford owner as the new Fords come with a 4 pin or the 7 pin round connection. So if you own a trailer with back up lights that are normally connected to anti-rollaway brakes, you can't electrically connect you 5 pin trailer to the Ford 4 pin flat connection. So the conversion from 7 pin round to 5 pin flat is the answer.


Much better than I expected. Delivered very quickly and met my needs to convert a 7 pin round Polack connector to a 5 pin boat trailer wiring harness. High quality molded plastic housing means this will last for a long while. I bought two both a 5 pin and 4 pin conversion. Both were priced right and I found them to be the best value I could find. Interesting my 4 pin unit had a cover for the 4 pin connection yet the 5 pin did not.


The easy afordable way to get the hydraulic brakes bypassed on my boat trailer when shifting in reverse. Saves you all the installation and wiring of a flat 5 pole set up. Only takes a few seconds to install and remove, doesn't take space in the trunk, great idea and product. Won't come off if you forget to remove it.


if you need a five pole like to a boat trailer so that you can back it up with the trucks back up lights are on it works good its the only trailer that has a five prong on it so I just leave it on don't really think about it because it works and its there


My new truck has a 7 pole socket and a 4 pole flat for OEM trailer wiring. My boat trailer has a 5 pin flat, so this is Just what I needed at a good price. As usual etrailer got it to me promptly. Puged right in and worked with no hassel.


It works just like it should. I had originally a 4 pin harness on my 2011 pathfinder but change to a factory 7 pin. I bought this 5 pin adapter to use with my boat trailer witch just need a connection to turn off the brakes when I reverse.


With disc brakes on a trailer, you need this to activate the lock out solenoid so you can back up the trailer. Convenient to use this if you already have a 7 pole round connector on your vehicle.


Once again, outstanding and prompt service by Although I have not yet used the 7-pole to 5-pin flat adapter I received it within 4 days and it is just as advertised. Always a pleasure doing business with

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