Attwood hull side bilge vents removed from a Sea Ray Seville but used on many other applications. 18” long and 3 1/2” wide. Requires a 16 1/4” by 2 1/2” opening. Also included is the hull vent duct with (2) 2 3/4” diameter holes for the bilge vent hose. This item is listed as the starboard side but may be used on either side if the duct is removed or reversed.