4" Silent Seal Easy Service Replacement Exhaust Flapper 

4" Silent Seal Easy Service Exhaust Replacement Flapper (Each)

These kits include a replacement flap, (2) two screws and (2) two flanges (front & back) to replace old or damaged flaps in Hardin Marine 4" exhaust tips.
These will fit in #410-281400, #410-281401, #410-281402, and #410-281403 exhaust tips.
These will fit in #410-280185, #410-280190, AND #410280195 Flap Assemblies.
The mounting holes are 1" apart

These flaps are 3.850" in diameter to fit the inside of the 4" Hardin exhaust tip.