Review on M1A2 Circuit Breaker Switch 40A Waterproof Fuse Inline Holder 3-15 AWG Resettable Fuse Manual Reset 12V-48V DC For Car Audio Sound Amplifier System RV Home Marine Boat Truck by Gary Stringfield

ordered this to install an amp with 4AWG wire on a boat. First I put threaded plugs on the wires, then red elastomer o-rings that fit very snugly against the wire insulation (it was a bit difficult to tighten at first). Then I stripped the wire, plugged it into the switch and tightened the set screws. Then slide the o-ring, close the breaker and tighten the end caps. The result is a nicely compressed O-ring that is good at keeping out moisture. The switch worked as advertised.