Sierra International 18-2171 Marine Engine Coupler Kit for Mercruiser Stern Drive Sierra Engine Coupler Meets or exceeds the original equipment quality Sierra part number: 18-2171 Interchangeable with the following: GLM 11500, Mallory 9-72502, Mercruiser 76850A2, 38965A1, 38965A2, 22492A2, 32492A3 and 32492A5 Fit specific, check part numbers to ensure proper fit