P-GM504 GM. Car ChipKeys (transponder keys) contain a computer chip in the head of the key programmed to the vehicle's security system. Duplicate keys require programming this matching code in order to operate the vehicle. The ChipKey blank is cut on a standard key cutting machine and programmed at the vehicle with a programming device. ChipKey is waterproof to protect internal chip. 1 each in clamshell. Incompatible with the Ilco key programming system.