Amarine-made Oval Garboard Drain Plug Stainless Steel Boat Fits 1'' Hole, Thread for 3/4'' High polished 316 stainless steel resists corrosion Provides bilge drainage upon haul out. Retention system keeps plug from getting lost Machined tapered pipe threads and o-ring ensure a water tight fit FITS 1-3/16" HOLE IN HULL RETENTION SYSTEM KEEPS PLUG FROM GETTING LOST