Machined bronze Garboard Drain & Plug provides drainage for bilge during haul-out. 1/2? NPT tapered thread plug provides a watertight seal with 2? diameter flange. Plug has a square top for use with a socket wrench. Installs with three #10 FH fasteners (not included). Description Flange w/Plug Size 2" dia Thread 1/2" NPT