Well show you the operation of the lock, its pretty easy. The key goes in and it works like a screwdriver. It just unscrews like so, then we can put it on our coupler. You put this through the lock hole on the coupler, which is typical of these latch style couplers. It just goes through then screw it together with the key, back it off a little bit with a turn. There you have it, locked into place and on the ball. Thats part # 63225 or #3008, the Tow Ready coupler lock.