Master Lock 377DAT Universal Trailer Coupler Lock, Chrome
Protect those unattended trailers with this rust and corrosion resistant universal coupler lock that fits 1-7/8'' and 2'' couplers. This nickel-plated coupler lock has an advance locking mechanism that resists picking and prying.
Binding: Tools & Hardware
Manufacturer: Master Lock
List Price: USD 33.33
Lowest New Price: USD 19.99
Price is accurate as of the date/time indicated. Prices and product availability are subject to change. Any price displayed on the Amazon website at the time of purchase will govern the sale of this product.
Customer Reviews


Good protection and economical
This is my second time purchasing this lock. The first one I simply lost when I didn't have it on.

I've been using this lock for over a year now and kept it on my trailer when stored outdoors all winter near Chicago. I have been pleased by its performance and durability. I was actually recommended this type of lock by a professional at a trailer/hitch installation shop.

I also saw a rumor that keys will work for various locks -- I found this un-true in my case as I had tried my other key.

I give this 5 stars for being a durable theft deterant at a reasonable price.


a great security device
This is a great lock. I don't see any way you could cut this off. You would destroy the tongue trying.


not secure
i own 2 trailers. first i bought one of these lock and find them to be ok. I feel that a couple of big hammer hit can remove them from the hitch, but will need work. So for the price i tought it's was ok.

Then, i bought a second one, at another store, on the other end of the city. i put it on my other trailer, put the key with the key of the others lock and leave this there for a week.

After a week i did obviouly forget to identify my key. SO i had to try it. ok key 1 in lock 1, woking cool. key 2 in lock 2, working... good i tought i was lucky. then i try key 2 in lock 1 working ? then key 1 with lock 2.... working ?!?

2 key with different tooth pattern work in booth my locks. what kind of lock is that. I finally endend removing these and i did put 2 DT security lock that do a much better job.

Bottom line. Buy something else. Anyone with a lock like this one can use hes key to open your lock.


Not great, not horrible.
The lock started to rust after only a couple of days outside. Overall the lock does not fit very well, it doesn't fall off, but for a 2" coupler it could fit better than it does. I honestly expected a better product than what I got.


Good Economical Way to protect your trailer
This product is a great way to economically protect your trailer - easy to use and tamper proof.