This cockpit scupper drain has been used by many builders for draining areas where the discharge is below waterline. Injection molded part is high strength and UV stabilized to provide value and durability. The check ball contained inside the cockpit scupper drain is molded and then ground smooth and round to provide better sealing against reverse water flow that occurs when backing boat. 90º fitting connects to 1-1/2 hose and installs with four #8 countersunk screws (not included). Top of cockpit scupper drain is removable for cleaning. Made in the USA ! Dimensions: The overall diameter of the top flange is 3 5/8″ Requires a 2 1/2″ diameter hole for installation Extends 3″ below flange If your cockpit drain looks like this, this is the one you need!