4 Inch Water Shutter that fits many Mercruiser applications.
It is 2-1/2" wide and 6-1/8" long
This valve has a butterfly action and comes with 2 grommets. Sold as Each.
If your flapper currently has square
grommets that hold it in, and a 4 inch Y-Pipe, then this is the correct flapper (except 4.3L with 1-Piece Manifold System)
If your current flapper is held in with round
grommets, then you need BPI89170