This Attwood Stainless Steel Straight Thru-Hull Valve Fitting installs securely and provides long-term corrosion-free performance. This is a barbed, standard-length fitting for use with 1-inch interior diameter hose. This fitting has a 2 ¼-inch flange diameter, a 1 3/8-inch thread outside diameter, and 2 1/4-inch thread length. The barb is 1 ¼-inches long, and the fitting's total length is 3 7/8-inches. The installation hole saw size is 1 ½-inches, there is a 1-inch NPSM thread, and the maximum hull thickness is 1 ¾-inch. Attwood Corporation has been an award-winning leader in engineering, testing, and manufacturing the highest quality marine products for over 100 years. We deliver safe and reliable lighting, fuel systems, water systems, seating & pedestals, swim ladders, custom upholstery, and general marine accessories that are easy to install and meet regulatory compliance.