1. Brand new heavy duty relays 2. 12 Volt 100 amp 4-Pin relays 3. Mechanical life of 10,000+ cycles 4. High 100A coil capacity- able to handle those high current applications with ease 5. Hundreds of uses include- starter kills, dome light 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....