Attwood 66551-3 Stainless Steel Barbed Standard Length Straight Thru-Hull, 1 1/2-Inch - Standard Thread has full length thread for thick hulls and easy tightening - Hose Size 1-1/2 I.D. - Flange Dia. 3 - Thread O.1-7/8 Thread Length 2-1/2 Barb Length 1-1/4 Total Length b4-1/8 - Install. Hole Saw Size 2 Thread NPSM 1-1/2 Max Hull Thick. 1-7/8