Seals tightly under water pressure – Thermoplastic duck bill flapper closes securely to block backflow. Universal replacement design – Matches most existing flapper scupper hole patterns for fast upgrades. Easy over-the-tube install – Slides over standard drain tubes for hassle-free installation. Durable marine-grade construction – Tough thermoplastic resists weathering, UV, and saltwater exposure. Outer ring diameter: 2-3/4 in – Sized to fit most OEM scupper tube setups and replacements. The T-H Marine Duck Bill Scupper provides a reliable, maintenance-free solution for keeping water out while allowing drainage on your boat. Constructed from tough thermoplastic, the duck bill-style flapper is designed to seal tightly under water pressure, delivering dependable performance in all marine conditions. Ideal for replacing worn or outdated flapper-style scuppers, this unit installs easily over standard drain tubes using a universal hole pattern. The compact, efficient design is compatible with most OEM or aftermarket scupper installations. Whether you’re restoring an old system or outfitting a new build, the T-H Marine Duck Bill Scupper offers superior sealing, a clean look, and durable performance in a simple-to-install format. Outer ring diameter: 2-3/4 inches.