Sierra 18-0860-9 O-Ring (Priced Per Pkg Of 2)Sierra replacement O-ring for Mercury and Mercruiser engines. I.D.: 3.237" or 82.2mm; Width: 0.103" or 2.6mm; Package of 2; Interchangeable with: GLM; 81520; Mercruiser Stern Drive; 25-62700; Mercury Marine; 25-62700; Mercury Sport Jet; 25-62700;