12 Volt 40 amp 4-prong relays Mechanical life of 10、000+ cycles Heavy-duty impact molded relay socket with 4 WIRES Interlocking relay sockets High 40A coil capacity- able to handle those high current applications with ease Hundreds of uses include- starter kills、 domelight supervision、 trunk release、 polarity change、power door lock/actuator control、 change a low current output to high current、add ignition/accessory outputs、 control motors/other electronics、 It is Also suitable for automobile used for control、 alarms、 horn、 headlight and more....Package include: 5 X 40A replay (4Pin) 5 X Relay Socket Wire