Description Replacement O-ring 1720-0213-SHW for sealing elbow fittings on Sherwood G2903 and 18000 series engine cooling pumps. Cross References/Supersedes: Not specified Application: Provides a leak-tight seal for pump elbow connections in Sherwood marine cooling systems. Compatibility: Used on Sherwood G2903-01, G2903-02, G2903X and 18000 series pump models. Usage: Typically installed in pairs, with two O-rings required per pump.