Bronze thru-hull fittings like these offer long-term durability in the marine environment.Bronze Threaded Thru-Hull Fittings for use above or below the waterline. Straight threads. Nut included.SizeMax. Hull ThicknessFlange ODSFPLU#Model1/2" 1 3/8" 1 1/2" 65-BN7-633563213/4" 1 1/2" 1 7/8" 65-BN7-504025701" 1 7/8" 2 3/16" 65-BN7-514133611 1/4" 2" 2 3/4" 65-BN7-524197801 1/2" 2 1/4" 3" 65-BN7-534096412" 2 3/8" 3 5/8" 65-BN7-543563603/4"5 1/2"1 7/8"65-BN8-0318409661"5 3/8"2 1/4"65-BN8-0418410551 1/4"5"2 3/4"65-BN8-0518411961 1/2"5"3 1/16"65-BN8-0618412462"5"3 11/16"65-BN8-071841279