Fittings to securely plug a drain hole, when opened on-the-hard to let out rainwater.All styles have a nut-type plug with 1/2" NPT threads for a watertight fit. All are cast bronze for corrosion resistance, with a 2" OD flange predrilled and countersunk for #8 screws (sold separately). Some styles have a stainless pin for easier plug removal by hand. Maximum hull thickness for styles with brass backing plate is 7/16".Key FeaturesStainless pin for easier plug removal by handCast bronze for corrosionBrass PlugBronze FlangePlugs fits standard 1" drains