Proven Locks Model S175: Trailer Hitch Lock,2 5/16-inch Trailer Hitch Lock, Fits Select 2 5/16- inch Couplers (2 5/16- Inch)

Really solid and well made. No way to get it off so don't lose the two keys. I feel safe leaving my trailer anywhere now. It is also easy to install and lock. Yes, you can't see the key hole but I have never had trouble getting the key to slip in the key hole and locking or unlocking it.

I’m using this on a trailer loaded up with our family’s dirtbikes. When we need to park the trailer it gets a lot of locks, and this looked like a good way to help keep the trailer right where I wanted it.No disappointment! It is a rhinoceros of a lock! Fit perfectly onto the lip of the 2” coupler, locking pin slides up into the coupler, key comes out smoothly. I like that the key is very non-traditional in shape and style, and that it turns the opposite direction to what you’d expect. Extra hiccups for the crooks out there, and honestly just looking at the thing is probably going to make most trash keep going for an easier grab. I realize any security can be defeated with time and determination, but this is a massive chunk of steel that won’t be undone quickly.If there’s a negative to it, it’s that the lock is really heavy, although that’s how physics works when you make something big from dense substances. You won’t forget this in your pocket. You may not have a pocket if you put it in there. I would buy this again in an instant but can’t see why I would ever need to.

Great coupler lock. Fits tight and securely. Better built than others I have looked at. Made in the USA!

I've been looking for something to lockup my Camper's hitch for a while, but haven't been able to bring myself to buy one of the more expensive "box" locks that fully encases the hitch. I stumbled on this while reading a camper forum, and it looked like an amazing compromise between quality/deterrence and affordability.It's a SOLID hunk of metal, and yeah while anyone with an angle-grinder is going to be able to get through it eventually, it's gonna make noise and take a bit. More likely the thief will just pick an easier target. It's also very thoughfully designed, as the keyhole is underneath, protecting it from the weather.The lock is also nice in that it's not the more common pin-style lock, so it's going to require a more experienced lockpicker to defeat it (might take the Lockpicking lawyer 5 seconds, but he's an exceptional talent). It's certainly beyond what I can do.The last little bit that's nice is that the manufacturer includes a card in there to contact them directly (not amazon) if you have any problems with fitment, and they'll swap it out for free. Excellent customer service even if I didn't have to use it.

The opening on this lock is 5" wide and 5/8" tall.Dislikes:The lock core can be hard to open with the key. If it only turns 1/4 turn, you need to jiggle the key to get it to engage all the discs.The key code is printed on the face of the lock where it is visible. I don't know if that's a real problem with these keys.Likes:The core seems to be pretty good. Looks to be a eight-disk core.It fits my trailer coupler very well.Seems pretty beefy. Much better than you would expect for the price.The locking bolt appears to be solid steel.The locking pawl is spring-loaded, but a shim attack would have to be from the top, where it can't be accessed.

Product is very substantial and heavy. Much better than other tongue locks on the market. Lock is easy to use even with the key hole being underneath the lock.

Easy to put on and lock up.

I have purchased another one from proven locks in the past and here I am buying another one from this great company.

Well made solid piece heavy metal