Check the listing for details. 1 inch hole Garboard Drain Plug Kit Boat Garboard Transom Scuttle Drain Plug. Condition: New. Listed at 13.36 USD. Real high-quality materials and precise processing, exquisite detailsFastener Holes are Precision Counter-bored for tight secure fit Recessed Fastener Holes are watertight and more resistant to corrosion and damage Replaceable Plug is 1/2 inch NPT Perfect for New Construction, Refits, Repairs and OEM replacement Requires #8 Fasteners2 inch outside diameter on the mounting flangethe protrusion in the back for the plug is 1 inch outside diameter and 7/16 inch deep on back for drain pipe Surface treatment The polished surface is even smoother, perfect for modern yachts and ships, and looks very upscaleSolid Brass Boat Hull Spare Garboard Drain Plug The material is very sufficient, not easily damaged, I feel very good in the hand, we do not use hollow like other productsSeiko processing Precision thread makes it more water resistant