Use: Prevent water from rushing in through exhaust thru-hulls when stopping, moving slowly or backing up. Fit exhaust pipes with an outside diameter (OD) of 4 inches. Package Includes: 2X Exhaust Guard Covers 2X Hose Clamps Replace: Part Number 50-28361 Mercruiser 12644A1 12644Q01 Serria 18-4457 Mallory 9-44001 GLM 89250 Details: Color: Black Size: 4" or 101.6mm Material: Weather resistant EPDM with U/V stabilizer and marine grade SS316 stainless steel