Stainless Steel Thru-Hull Standard Straight Barbed – 1-1/8in Inner Diameter. 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 Thru-Hull 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 Straight Thru-Hulls, Barbed Standard Thread model has a full-length thread for thick hulls and easy tightening. Specifications: Hose size: inch 1-1/8in inner diameter. Flange Diameter: inch 2-1/4in. Thread O.D. outside diameter: inch 1-3/8in . Thread Length: inch 2-3/8in. Barb Length: inch 1-1/4in. Total Length: inch 3-7/8in. Install Hole Saw Size: inch 1-1/4in . Thread NPSM: inch 1in. Max Hull Thickness: inch 1-3/4inSteel Thru-Hull Connectors are designed for installation above the water line only