There will be two rectangular holes for the grommets. If your Y-pipe has round holes you need the A3 water shutters. If your Y-pipe changes size a few inches bellow the shutter you have a one piece manifold V6 Y-pipe and need shutter A2. The replacement part is made from high quality material and well-tested by the manufacturer. Please check carefully the part numbers and compare pictures provided to insure proper fitment. Note: These will Not work on V6 engines that came with piece manifolds ( use 807166A2 it has a flat tip ) ,or early with the round pin going through flapper. Used on many stern drive engines. ( Some V6 that came with the two piece maniflold/elbow ) If you have ever overheated these tend to get damaged. Sometimes you will find pieces of them in the exhaust when you remove for servicing. They help keep water from entering the engine through the exhaust. Condition: New Size: .15.6x7.9 cm(6.14x3.11 inch) (LxW) MPN: 807166A1 Compatible With: fit for V6/ 1996-1999 Colour: black Material: ABS Package Contents: 2 * Exhaust Flapper Water Shutter Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.