Core Trax Tie Down System Accessories. This has Extra Load Locks and a Pet Safety Cable. The Pet Safety Cable attaches to the Load Lock on the Core-Trax Tie down Track System. The Pet Safety Cable is a 2' long cable that attaches to the Load Lock on one end and attaches to your pet's collar with the other end. The Pet Safety Cable makes it easy and safe for you to travel with your pet in back of any truck, van or SUV. You can also get extra Load Locks to fit on your Core-Trax Tie down Kit. The Load Locks can be quickly attached in every 1" increments along the track for the ultimate tie down system.