Genuine Mercruiser 807166A1 Exhaust Water Flapper
Genuine Mercruiser exhaust butterfly flapper shutter fitted to a huge range of Mercruiser V6 4.3 and V8 5.0, 5.7, 6.2, 8.1 and 8.1 inboards in the exhaust Y pipe out of the transom.
This is a genuine Mercury part.