Stinger SGP32 SGP Series 200-Amp Relay and IsolatorStinger SGP32 SGP Series 200 Amp Relay and Isolator 200 amp constant; 500 amp peak current; Prevents primary battery discharge; ideal for second audio battery isolation from vehicle systems; Compatible with all types of alternators and charging systems; Maximum current transfer; high current relays are the most reliable and efficient way to add secondary batteries to a system; Water resistant black phenolic plastic; 100,000 mechanical cycle life;