Perko 1-1/2" Thru-Hull Fitting w/ Pipe Thread Bronze. Flange is machined to fit hull and grooved to retain bedding compound. Neck is threaded to approximately 3/8 inch from flange.. Cast bronze.. Technical Information:. Pipe Size Inches: 1-1/2. Mouting Hole Diamete Inches: 1-7/8. Maximum Hull Thickness Inches: 2-1/4. O.D. Flange Inches: 3. Model Number: 0322DP8PLB. Ship Weight: 7.6/15.0 lbs.. MADE IN THE USA