My husband relies on me to make sure he has the parts and equipment he needs to repair things around our house. Recently, he told me he needed a magnecraft relay for high DC switching. I am not sure what he needed it for, but since he was specific with what it was called, I easily found the part online and purchased it. The only thing I know about relays is that they are used for isolating one circuit in order to make another voltage circuit compatible in machinery. I do not know what kind of machinery he fixed with the relay I bought, but I do know he was happy I got the right one.