The Cruisemaster™ DO35 Lock assembly consists of a dummy pin, two keys and lock chamber with dust cover.

How does it work? The dummy pin is inserted into the DO35 universal joint from the top end and the tip of the pin protrudes out at the bottom. The lock is then fitted to the protruding end of the pin and locked with a key. The coupling becomes inoperable which prevents others being able to hitch up to your trailer or van when you're not there.