Drilled Solid Rubber Stoppers Bungs For Home Brewing, Beer Wine Making, and Laboratory Use. Pure gum laboratory stoppers manufactured from premium grade rubber. Order with or without drilled hole. Hole size is 3/8" which works with most airlocks. Color is white to off-white. #2 fits beer bottles. #3 fits most wine bottles. #5 fits 125 ml Erlenmeyer flasks. #6 fits 1 gallon glass jugs, 1,000 ml Erlenmeyer flasks. #6.5 fits 3, 5, 6, and 6.5 gallon glass carboys. #7 fits 3, 5, 6, and 6.5 gallon glass carboys. #7.5 fits some older 3 gallon glass carboys. #8 fits 1,000 ml Erlenmeyer Flasks from MoreBeer! and Fermentap. #10 fits plastic PET 3, 5, and 6 gallon carboys. #11 fits in sanke keg opening if spear is removed, also fits most large wooden barrel holes as well as demijohns. Universal Medium Bung fits 3, 5, and 6 gallon size plastic PET carboys and Better Bottles. WE ARE NOT RESPONSIBLE IF YOU ORDER THE WRONG SIZE SO PLEASE REFER TO THE FOLLOWING STOPPER SIZE CHART FOR SPECIFIC DIMENSIONS. SIZE TOP BOTTOM LENGTH INCHES MM INCHES MM INCHES MM #000 1/2 12.7 5/16 8.2 13/16 21 #00 19/32 15 13/32 10 1 25 #0 21/32 17 1/2 13 1 25 #1 3/4 19 9/16 14 1 25 #2 25/32 20 5/8 16 1 25 #3 15/16 24 23/32 18 1 25 #4 1 25 3/4 20 1 25 #5 1-1/16 27 29/32 23 1 25 #5.5 1- 3/32 27.5 15/16 24 1 25 #6 1-1/4 32 1-1/32 26 1 25 #6.5 1-11/32 34 1-1/16 27 1 25 #7 1-7/16 37 1-3/16 30 1 25 #8 1-5/8 41 1-5/16 33 1 25 #9 1-3/4 45 1-15/32 37 1 25 #10 1-31/32 50 1-5/8 42 1 25 #11 2-13/64 56 1-7/8 48 1 25 #12 2-1/2 64 2-1/8 54 1 25