Description: Material: Cork Height: 30 mm / 1.2 inch Firmly holds round bottom flasks, outer diameter is from 80 to 160 mm High quality cork of good elasticity, strong heat and electrical insulation, friction resistance Non-toxic, Non-flammable,and eco-friendly Specification: Please note that different sizes of stands are adapted to flasks of different volume, here is your reference: Stand of 80mm Diameter: 50-250 ml round bottom flasks Stand of 100mm Diam.: 150-1000 ml round bottom flasks Stand of 120mm Diam.: 500-3000 ml round bottom flasks Stand of 140mm Diam.: 1000-5000 ml round bottom flasks Stand of 160mm Diam.: 3000-20000 ml round bottom flasks Package Includes: 1 Piece cork stand Note: Please allow 1-2 mm inaccuracy due to manual measurement. Thanks.