S.152756 Seat Safety Switch, Normally ClosedOne New Aftermarket Replacement Seat Safety Switch (Normally Closed) for Agricultural and Lawn & Garden Equipment This operator presence seat safety switch is a normally closed (NC) replacement designed for tractors, lawn and garden equipment, and other agricultural machinery that use a screw mount or twist mount style seat switch. A normally closed switch allows current to flow in its unactivated (uncompressed) state meaning the circuit is engaged