Feature: 20A/30A/40A/50A heavy duty automotive circuit breaker. For use with 12V electric fans, head lamps etc. Single pole, auto-reset model. Mechanical life of 10,000+ cycles. Weatherproof air-tight housing. Easy plug-and-play design. Great replacement for thermostat kits. This product is designed to allow a current under 50 Amps to-flow to keep wind turbine generators from burning out. An electric current in excess of 50 Amps will overheat the breaker causing the fuse to auto disconnect stopping the currents-flow. When the current drops under 50 Amps the breaker will cool and electricity will start to flow-again as the continuity is restored. Specifications: Type：automotive circuit breaker Current Rating：20A/30A/40A/50A optional Application：Automotive Volt：12V Application: Battery Chargers, Trucks, Buses, RVs, Trolling Motors, etc. Package Included: 1*circuit breaker Note: Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Manual measurement, please allow 1-10mm error. Thanks for your understanding. 20A/30A/40A/50A heavy duty automotive circuit breaker. For use with 12V electric fans, head lamps etc. Single pole, auto-reset model. Mechanical life of 10,000+ cycles. Weatherproof air-tight housing.