This watertight gas fill from Perko is made of chrome-plated zinc alloy with a black polymer flange and cap with strap. Includes grounding screw, cap retainer, and gasket. Fits 1-1/2" I.D. hose.• Flange: 3-1/8" O.D.• Neck: 1-7/8"L• Mounting Hole: 2-1/8" dia. Fits 1-1/2"" I.D. hose 2-1/8"" dia. mounting hole | Perko Non-Locking Gas Fill for 1-1/2" Hose in Black