This Attwood Stainless Steel Garboard Drain Plug is threaded for easy removal and sure insertion, and it has a retention system that helps prevent the loss of the plug. This plug has a large, 7/8-In. (27mm) hole for servicing stern drives. It is made of #316 stainless steel for a bright finish and to resist corrosion. Attwood Corporation has been an award-winning leader in engineering, testing, and manufacturing of the highest quality marine products for over 100 years. We deliver safe and reliable lighting, fuel systems, water systems, seating & pedestals, swim ladders, custom upholstery, and general marine accessories that are easy to install and meet regulatory compliance.