757-15721 Oil pressure switch, Lister Petter oil pressure safety switch used on LPA, LPW2/3/4, LPWS, LPWT, TS, TR, HR, SR enginesThis is a very commonly used low oil pressure switch used in the Lister Petter line of engines. You'll find it in almost every LP engine ( LPA, LPW S T G, TS TR, SR, AB AC AD engines). It can be adapted easily into almost every LP model of engine. The connections are C for Common, NO for Normally open and NC for Normally closed. The trigger point is set at approximately, 7 psi. Some electrical schematics you will see may show 2 wires on the drawing