Narva 12V 50A Normally Open 4 Relay with Resistor Protection Blister Pack is designed for use with variety of applications where switching of high power is needed, such as auxiliary lighting, heating fans, wipers and air conditioning equipment. The relays feature silver contacts for durability and a removable metal mounting tab for convenient installation. The relay is rated to 500, 000 cycles and features a braided power strap for increased reliability. The relays are available with resistors to protect sensitive electronic equipment from voltage spikes.