Head car keys are all-in-one key and remote control devices. The key has a traditional shaft that is cut to fit into your ignition. The key’s “head” (the part of the key you hold), contains a transponder chip. This chip communicates with your car’s security system to allow the car to start. Your remote head key generally has additional remote control buttons to operate door locks, and release the trunk. You may also have a “panic” button that loudly blast your horn if you are being threatened.