Each Thru-Hull and Scupper Valve is available with a new silicone gasket and are backed by Attwood's trusted Lifetime Warranty! Why specify plastic parts when these fittings will last the life of the boat. The Scupper Flap is tough neoprene ruber with a molded V that fits into the grooved body to reduce back wash. Fastners are concealed and corrosion-proof. Rugged Stainless Construction Cast from certified enhanced #316 Stainless Steel allow for strength and lifetime corrosion-resistance We polish all visible areas to a mirror finish, then each part through a passivation for additional protection Thick steel sidewalls withstand continual stress and hose flexingSolid Solicone Gasket Gasket is dimensionally stable--will not deteriorate or shrink over time Excellent resistance to UV & weather-aging Watertight, fool-proof, one-piece seal Eliminates the need to form and apply sealant or caulkCaution: Thru-Hull connectors are designed for installation above the water line only. Lifetime Warranty Hose size 1-1/2" I.D. Flange Dia.1-7/8" Thread OD1-3" Thread Length 3-1/1" Barb Length 1-1/2" Total Length 5-1/2" Install Hole size 2" Thread NP SM 1-1/2" Max Hull Thickness 3" Bulk without Gasket 66553-1 Bulk with Gasket 66553G1