Cast bronze. Flange is machined to fit hull and grooved to retain bedding compound. Neck is threaded to approximately 3/8" from flange. Includes flange nut. UL Listed.THRU-HULL CONNECTION (PERKO)SKU: 85226035944$41.59PriceQuantity*Add to CartFeaturesHose1/2"Flange1-1/2"Max Hull1-3/8"