This light weight lock comes with a retractable coated steel cable and three digit combination lock you set to your own numbers. The lock cable threads through handles or loops built into Pack-Right car top carriers, zIpper pulls, and around your luggage rack. You can purchase two one for each side of the bag. The locks help prevent the bad guys from simply unstrapping your car top carrier and lunch stops or gas stations. For ultimate security we do not recommend leaving your car top bag on the car overnight.