The MAXTRAX Mount is an ingenious way to mount 2 or 4 individual MAXTRAX to the side or the top of your K9 Roof Rack System. Designed to be used with the MAXTRAX Mounting Pin Set, which are high-quality black nylon and stainless steel quick-release pins (not included). The hole in the top of each pin is compatible with a TSA-style padlock. The mount has a flat back surface, and utilizes one of the included K9 Accessory Adapters to attach to the top of the rack. Set includes (2) mounts.