These receiver locks from Bolt feature a solid zinc core, an automotive grade cylinder with a patented 6 plate tumbler sidebar to prevent picking and bumping, and a stainless steel lock shutter to help keep out dirt and moisture. They are also equipped with a rugged jacket and cap. Bolt receiver locks are ideal for helping you secure your hitches by conveniently using your ignition key. That means you will not have any extra keys to carry or lose and that you will have the convenience of always having the right key.