Retrofit your old flapper style scuppers with the Rabud SeaScupper and make your deck self-bailing! For use with drain tubes from 1" to 3"  in diameter. Polycarbonate housing with long-life PVC gasket. Solid Polypropylene ball prevents water from intruding. U.V. stabilzed for harsh environments. Features mounting holes at 2, 4, 8, and 10 o'clock positions.