This is a A-3902089 O-Ring, Water Pump Sealing PN: 3902089Main Description As Following : A-3902089 O-Ring, Water Pump Sealing P.N: 3902089 A-3902089 O-Ring, Water Pump Sealing P.N: 3902089 Found in Section & Models : Engine Parts > 6-830T Turbo Charged Cummins "C" Series, Case-IH COMBINE: 1660, Case-IH COMBINE: 1666 (Engine SN 44706126>), Case-IH COMBINE: 1670 (Engine SN <44706125), Case-IH COMBINE: 1680 (Engine SN <44706125), Case-IH COMBINE: 2166 (SN