When you need short circuit protection for a 40 amp circuit, this Bussmann Shortstop circuit breaker is the one to use. The main advantage to using this 40 amp Automotive circuit breaker over a fuse is that in the event of a circuit failure, the circuit breaker does not need to be replaced. This reduces down time of your equipment, especially if you don't have a spare fuse handy. shortstop circuit breakers have been used reliably in the industry for many years, and have a proven track record of reliability. This particular bussmann breaker is rated for use in 12 volt DC electrical systems. it features a parallel mounting bracket attached to the bottom of the body of the circuit breaker to allow it to be easily attached to any surface. The two studs and included nuts are used to attach your wiring to the circuit breaker. The automatically resetting functionality allows the breaker to be mounted in hard to access locations, as no human intervention is required to reset it. With a 40 amp current carrying capacity, this breaker is suitable for protecting larger gauge wire such as 8 gauge, and higher power circuits such as amplifiers and inverters.