For use with the PROMAX Refrigerant Recovery Machines that do not have internal wired jack for the KT-5002 overfill protection plug and cable. Some late model units do not have the 3 wire socket installed from the factory and this will be needed to complete the installation of your float cable kit. Installs in minutes and is completely compatible with factory wiring. Simply open case and remove the white two wire jumper on the coil of the relay to the far right (pins 17 & 47) and replace with this plug. Then install the ProMax KT-5002 and your done.