Stainless Steel Scupper Valve Barbed – 1-1/2in Hose Size. Polish your image with these beautiful, durable stainless steel fittings. Why specify plastic parts when these fittings will last the life of the boatRugged Stainless Construction: Cast from certified Enhanced 316 Stainless Steel alloy for strength and lifetime corrosion-resistance. All visible areas are polished to a mirror finish, then passivate each part for additional protection. Thick steel sidewalls withstand continual stress and hose flexing. Faster, Simpler Installation: Each Scupper Valve is available with a new silicone gasket. A channel under the flange holds a bead of sealant, making it easier to apply a trouble-free seal. All models have wrench flats or an end notch to hold as a gripping surface; one installer can tighten all connections from inside the hull. The barbed tail ends provide plenty of room to hold multiple clamps. Stainless Steel Scupper Valves, Barbed: The Scupper Flap is tough neoprene rubber with a molded V that fits into the grooved body to reduce backwash. Fasteners are concealed and corrosion-proof. Specifications: Hose size: inch 1-1/2in inner diameter. Thread Diameter: inch 1-7/8in . Flange O.D. outside diameter: inch 3in. Thread Length: inch 3-1/2in. Barb Length: inch 1-1/2in. Total Length: inch 5-1/2in. Install Hole Saw Size: inch 2in . Thread NPSM: inch 1-1/2in. Max Hull Thickness: inch 3inSteel Thru-Hull Connectors are designed for installation above the water line only