attwood Plastic Thru-Hull Connector Standard Thread has full length thread for thick hulls and easy tightening Hose Size: 1 1/2" I.D. Flange Dia.: 1 7/8" Thread O.D.: 1 7/8", Thread Length: 2 1/2", Barb Length: 1 1/4", Total Length: 4 1/8" Install. Hold size: 2", Thread NPSM: 1 1/2", Max Hull Thickness: 1 7/8"