Flapper - Exhaust 4"
Sierra Exhaust Protector Valve #18-4456D Size" 4". Complete with Stainless Steel Clamps. Replaces: Mercury 12644A Premium Protector Valves for wet exhausts are made of 100% durable EPDM that is extremely resistant to UV light, ozone, heat, and weather aging. For salt or fresh water. It will give the boat's exhaust system dependable protection in any harsh marine environment.