MEGA, LOC-IT, Underslung Coupler Lock. Fits Jayco Ram, Curt and Generic Underslung couplers. This is a fully welded steel housing as you can see. Once placed on the coupler, and locked you Can't Pry Off and is Bolt Cutter Proof.  Fits 2 5/16 ball Couplers up to 5 1/4" wide at the ball flange. This lock will be mounted with the ball latch is engaged, leaving you with the opportunity to place an additional lock on the latch, for more security. The purchase includes the housing, locking pin and puck lock with 2 keys, and instructions. There is also a 90 day Warranty for manufactures defects.