Sierra's 18-7115 O-Ring is designed for use in select Johnson/Evinrude, Mercruiser, Mercury, and OMC engines. The o-ring features a 1.735" I.D. and a 0.135" width. The package includes one o-ring. It is interchangeable with GLM 82240; Johnson/Evinrude Outboard 302588; OMC Stern Drive 302588; Mercruiser Stern Drive 25-20266 and 25-26722; and Mercury Marine 25-20266 and 25-26722. Check manufacturer recommendations to ensure a proper fit before purchasing. Each Sierra product meets or exceeds the original equipment part it replaces.