The Bi-lock is the one of the most effective deterrents to keep your trailer safe when parked. 

Designed to work specifically with the DO35 hitch, the Bi-lock  locks on to the the hitch rendering the camper inoperable for towing. 

What you need to know: 
* The Bi-lock keys must be registered to the owner
* Is suitable for DO35 V2, V3 and V3 Plus