13x100mm Test Tubes with Cork Stoppers and Cardboard Rack, Borosilicate Glass, Round Btm, 7ml Vol, Karter Scientific 220D6 (Pack of 25) Go to amazon.com Related posts Top 8 recommendation test tubes glass for 2022 Feature13x100mm Borosilicate Glass Test TubesSize 3 Cork StoppersVolume: 7mL. External diameter of tubes are 13mmRound BottomCardboard Rack DescriptionKarter Scientific 13x100mm Borosilicate Glass Test Tubes with Cork Stoppers (Pack 25). Including a Cardboard Rack