Use the safety chain to loop over the top bar and use the padlock to lock the end of your safety chain. It is possible to tow a trailer with a safety chain so the above procedure prevents thieves using this chain.
Dual Lock is a security lock that helps prevent your trailer from being stolen from the boat ramp or even from outside your home. Notice how Dual Lock covers the nut under your two ball to prevent the nut from being undone.
Most trailers are stolen from either unfenced or unsecured storage areas. Some small trailer locks are easy to break with a good whack from a standard hammer.

Dual Lock is made from 8mm solid steel plate and is cadmium plated to prevent rust.
If your investment is to be protected then in our opinion the value of your trailer locking mechanism should be relevent to the value you wish to protect.
Fit's most 2" couplings, unconditional money back guarantee. What's different about COUPLEMATE trailer locks? OK, the COUPLEMATE GROUP of products are all researched, manufactured and tested to work properly.
TIP: If the trailer lock fits loosely place a section of the safety chain under the locking bar.
NOTE: Please don't travel with this trailer lock in position as it is likely to be buckled when extreme angles accidently occur when parking or backing. In extreme cases when cornering the load from the trailer and the momentum created when negiotating tight corners at speed can cause and has caused trailer roll. This device locks the trailer to the car and can cause the entire rig to roll if left connected during your travel. If you wish to travel with a trailer lock in place then use the Couplemate Guide and Lock device.