Get full-time electronic surge protection for a car, bus, marine vessel, heavy industry, or agricultural equipment. Simply install the 12-volt heavy duty AntiZap Surge Protector permanently across the battery terminals, and wait for the green LED indicator to light. When the the green LED is lit, it indicates the connection is correct, and Antizap surge protection is active. The red LED lights if there is no surge protection. The heavy duty housing is weatherproof and shockproof. Install leads are terminated in tin-plated, crimped, heavy gauge solid copper lugs.