Master Lock Trailer Lock, Universal Trailer Coupler Lock, 379DAT , Silver , Standard

good value

I needed some locks for heavy-duty trailers that use 2-5/16" Bulldog couplers. I had previously had bad luck with Guardian locks, which were more expensive, not as well made, and not backed up by the manufacturer.These Master Lock coupler locks not only appear to be much better locks, they come with a limited lifetime warranty from Master.This lock fits the Bulldog/Hammerblow couplers and is a very reasonable price. Fortunately, I cannot say how well they resist thieves' attempts to steal the trailer, but they will certainly provide a substantial deterrent.I bought mine in October 2008 and they did not have a rubberized coating nor a keyway cover. They have a chrome finish that appears to be excellent. Despite being in the weather all winter in Indiana, they still look and operate as if they were brand new.Edit, 1 January 2012: I see that Amazon also sells Master Lock model 379ATPY. That lock appears to be closer to the model I bought back in October 2008. In spite of the listing on that item's page, it also fits 2-5/16" ball couplers, just as this one does.I have since bought this exact model, the 379DAT, with the rubberized coating. It seems to be a bit looser on the coupler, I think because of the coating. Unless you are concerned about the possibility of the coupler's paint chipping from metal-to-metal contact, I would recommend the model 379ATPY over the 379DAT.Both of these locks remain highly recommended.

Not sure seams a little loose fitting will deter the honest guy

I had the Yellow hoop design trailer tongue lock and misplaced the keys. I put a prybar between the trailer tongue and the yellow part right by the lock and it popped off in 2 seconds. Literally all show and no protection. This one looks much more useful.

They have updated the picture and it does show the lock as I received it. It fits and locks my Haulmark trailer and boat trailer both without any issues, both have 2" balls. It serves it's designed purpose well. It gives me some peace of mind knowing that someone can't simply back up and drive off with our boat or cargo when we are on trips.The unit feels fairly robust but sadly the keys are weak. I found if I wasn't careful the metal key bent when using it to get my setup installed and removed. To assure I didn't have a key break I made a copy and have been using the stronger copy key now. My particular key had a weaker spot due to a deep cut in the pattern of my lock so this may not be an issue for you.

This lock is functional, but it does not feel very sturdy. Obviously a lot of the construction is plastic, but the inner metal portion doesn't feel very solid either. I haven't tried, but it seems like you could pry this off with a crow-bar.Some of you will note that this type of lock is usually meant to discourage (not prevent) a thief. In this aspect, the lock met my expectations. Still, I can't see someone being overly discouraged by this lock.As far as postiives, I like that the key hole has a cover, and after using this for about a year, I haven't noticed any fading or discoloration.Buy it, if you like, or consider a more expensive (and more secure) option. I'll keep using it, but I wouldn't buy it again, if given the opportunity.

This hitch lock looks good and I expect will foil the casual thief. It seems to me an aggressive thief could pry this lock off, but of course I have not tried it. It fits a little loosley in my 2 5/16" hitch but does it's job.My main complaint with this lock is removing the insert that fits into the hitch ball area as it slides backwards to release the lock. Almost every time when taking this off we have ended up with nasty grease on your hands from inside the hitch ball area. I highly recommend using disposable plastic gloves when removing. Obviously a learning curve to pay attention to this messy situation.I do recommend the lock and would buy it again, just be aware that it can be messy.

Fits perfectly in a boat trailer hitch.

Gives you peace of mind knowing someone can't easily steal your trailer. Very easy to use.

Was looking for a secure lock for my RV and most options were only protecting the top latch. Very easy to use and reassuring to have a Master Lock.

Very happy with it.

easy to use

Remorque