Replaces part #s 50-28351 Sierra 18-4456 Mercruiser Stern Drive 34765A2, 34765A 18-4456 Aqua-Power 5018 GLM 89240 Mallory 9-44000 Redline RL4456 Prevent seawater from entering the exhaust port when stopping, slowly moving or retreating Prevent seawater from entering the exhaust port when stopping, slowly moving or retreating Includes: Stainless Steel Clamp Pack of 2 exhaust guard covers with clamps Replaces part #s 50-28351 Sierra 18-4456 Mercruiser Stern Drive 34765A2, 34765A 18-4456 Aqua-Power 5018 GLM 89240 Mallory 9-44000 Redline RL4456 Prevent seawater from entering the exhaust port when stopping, slowly moving or retreating