Sierra 18-5899 Oil Pressure Sending Unit for Mercruiser, Volvo, OMC Sierra replacement oil pressure sender. Used on most types of marine applications on sterndrive and inboard engines. All Sierra aftermarket engine parts are manufactured to meet or exceed OEM requirements. Specifications Sender Code C Range - 80 psi Thread Size - 18-27 Terminal Type - 10-32 stud Use with 80 psi electric oil pressure gauge. Replaces Crusader 700425 Mercruiser 815425T 90806A 34623 90806 815425 8M0068784 OMC 172127