Ram Sliding Collar Coupler Lock - Fits ONLY RAM coupler

Pretty substantial, heavy built, your trailer is advertised as "hard to get" with this on (didn't lock up my last trailer and it was stolen out of my side yard). The only thing that could make it better is if it had a lip that went into the ball area, but don't know if that would make much of a difference. If you want it off without the key you are going to have to use a torch.

This model fits bulldog hitches. It is the best locking system I have found as far as most difficult to remove by a thief. I am really pleased with the ones I bought and would highly recommend it to others.

This company makes nice products. Have 3 of their products. Havent had anything stolen yet.

It really looks secure and pry resistant.

Best lock out there. Period

Very solid construction

Best trailer security I have found yet. Mine in 6months old, still holding strong. Doesn't look like anyone has attempted to mess with my trailer. Nice bright heavy construction. Would recommend to friends.2021 update. Still in good working order, still bright yellow. Good buy.