High quality medium size drain plugs UV resistant nylon material with a neoprene "O" ring seal and full flow retainer ring design. This medium 25mm internal flow size gives 50% larger drain capacity than standard sized 17mm internal flow drain plugs. 25mm internal flow size. 30mm cut-out hole. 2 x 4mm countersunk fastening holes. Available loose (bulk) no packaging - or also available retail hang packaged. Black or white colour.