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Worried about your trailer being towed away by thieves? The Master Lock ML377KA offers a robust solution with its advanced locking mechanism designed specifically to deter picking and prying. This means you can leave your trailer secured with peace of mind, no matter where you park it.
For those who park their trailers exposed to the elements, corrosion and rust can be major concerns. The gray-coated die-cast zinc construction of this lock provides exceptional resistance to weather-related wear, ensuring your lock remains reliable and functional for years to come, even after being subjected to harsh conditions.
Own multiple trailers with different ball sizes and brands? No problem! This lock fits 1-7/8", 2", and 2-5/16" ball diameters across several coupler brands including Reese, Fulton, and Atwood. This versatility allows you to use the same lock for various trailers, simplifying your security needs.
Hate fumbling with different keys for different locks? Order multiple Master Lock ML377KAs, and they'll come keyed alike. This convenient feature ensures that you can easily manage multiple locks without the hassle of keeping track of individual keys, especially beneficial if you operate several trailers.
Nobody wants to struggle with cumbersome installations. The Master Lock ML377KA offers an easy-to-install and remove process, perfect for those on the go. You'll appreciate this simplicity whether you're frequently hooking and unhooking your trailer or just setting it up for the season.
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hello everybody, this is Jeff at etrailer.com. Today we're gonna take a look at this Master Lock trailer coupler lock in the gray finish, and it can be keyed alike. Now this is a gray-coated die cast zinc trailer coupler lock and it'll lock onto your trailer coupler and guard against trailer tow way theft. This one here you can see has a nice gray zinc finish to it that'll resist rust and corrosion, and it is designed to fit most 1 7/8 inch, 2 inch, and 2 5/16 inch ball diameters. And they'll fit the following coupler brands. They'll fit on the Reese, the Fulton, the Atwood, the Putnam, Marvel, Ideal, Acme, and the Dutton-Lainson.
Basically, your coupler just needs to have a flat lip on it no larger than 5/8 of an inch wide. And just to show you what we're talking about, I happen to pull a coupler right here. You can see this fits onto a 2-inch ball and you can see it's the trigger latch design. And when I mentioned the flat lip, if you notice this flat lip that goes around the front here, as long as that's no longer than 5/8 of an inch, it'll work on this lock. But you do need that flat lip for the lock to work.
And just to show you how that works, it's pretty easy to install and remove. Basically this locking mechanism, we'll first go over that. If you look right here on the locking mechanism, if you see real close, there's actually three positions it offers. There's one dot over here, one at the very top and then one right here. Basically what that is, the position one, which is the one furthest right over here, this will allow you to freely move the shackle.
You just hold the key in there and you can move the shackle back and forth. Once you let it go, it's spring loaded. Guess I can show you that, we'll go ahead and put the key in there and you can see if I turn it all the way over to one, you can slide your shackle back and forth. Now, once you let the key go, it'll spring load back into the position number two. And what position number two does is, it'll let you ratchet the shackle toward the ball coupler.
So you can see just like that. And then you turn it, bring it out. Once it goes back into two, you can ratchet it toward the coupler and then position three, which is way over here, if you just turn it to that position and remove your key, that keeps it in the lock position. So now what I want to do is demonstrate it on the ball coupler. So we're gonna take it all the way out this way and then you'll take your, open the latch, put it over there, push it down, go ahead and latch it into place. And now you're latched on and your lock is on there. But then the thing you want to do now, to lock it into place, you just, you're in the position number two, so you can push it all the way, turn it to three, pull your key out, and now it's locked. It's not going anywhere. So if somebody, this'll stay attached to your trailer. So if somebody wants to try to hook up to your trailer, and they open the latch just like that, even though it's unlocked, you can see it's not gonna let anybody get into there and hook up and take it away. So either locked or unlocked, it's still gonna have the coupler lock on it. And then to remove it, again, it's in the three position, turn it all the way over to the one, slide it out, let it go. And then you can remove it just like that from the coupler lock. So as we mentioned, it's very easy to install and remove. Two keys are included. And the other feature on this, this lock can be keyed alike. If you're ordering more than one lock, you just go up on the top of our product page on the right hand side and you'll see a box that'll say keyed unique or keyed alike. If you want 'em keyed alike, just go ahead and select that. But that should do it for the review on this Master Lock trailer coupler lock in the gray finish.
There had been evidence of someone trying to break into our trailer and we feared it would be easy for someone to hook up to it and pull it away. This trailer coupler lock is a great deterrent from thieves. It eased our minds and it's cost was very reasonable. Best of all, our trailer hasn't been stolen!
It looks good i think the ball could be a little bit bigger for 2 5/16 ball i think it will do the job thanks
I was a little sceptical about the lock when I first received it. I installed the lock and did my best to remove it without using the key. If I had tried any harder I would have damaged my trailer. Very good quality and affords a great deal of comfort in knowing my trailer will still be there in the morning!
This lock is perfect—fits like a glove and easy to use. The etrailer staff is always very helpful and easy to work with. They were happy to answer my questions and kept me posted on the status of my order. 5 stars!
After about 8 or 9 times locking and unlocking key became stuck in the unlock position. Could not get it out or lock it. I tossed the pos in the river.
I bought 4, keyed alike, of these. They are very solid.
With 2 trailers with 2" couplers and 2 with 2-5/16" couplers it is very handy to have them keyed alike, also, they work equally well regardless of the coupler size.
I would recommend these whether you have one trailer or 4 like myself.
Worked great
Does not work with 2 5/16" hitch.
I love a business that exceeds my expectations. The Master Lock arrived BEFORE the promised date, and it was just what I ordered with no hassles. The Master Lock is well built, fits over my trailer coupler perfectly, and works flawlessly. I am confident that it will provide years of trailer theft protection, while withstanding the harsh environmental elements.
I think it will work
Exactly what was needing for my trailer.
Locks work good. I bought 3 keyed alike.
I have used etrailer several time and have absolutely Excellent service.
Delivery time rivals Amazon!
Great communication...my order arrived early. Happy with the quality of the parts. Very happy with my transaction.
Just what I needed
Great Product just as advertised.. and the communication about a delayed shipment date was immediate and accurate... (acutally came a few days eariler than expected) .
Thanks for the great service
I think they are great
Heavy and secure
Great customer service. Fast shipping part came really quick.
Very nice item.
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Patsy
2/19/2025
The trailer coupler lock is in as good of shape as we purchased it. Since our trailer is stored outdoors, this is important! I recommend this product for keeping a trailer safe from being stolen.