Specifications: Can be used for test tube, flask stopper or other bottles. 15 different sizes for ypur choice, can meet your different needs. Type: Rubber Stopper Material: Rubber Quantity: 1Pc Size Details [Our Size 000#] Bottom Diameter: 0.9cm/0.35"", Top Diameter: 1.3cm/0.51"" (Approx.) [Our Size 00#] Bottom Diameter: 1.1cm/0.43"", Top Diameter: 1.5cm/0.59"" (Approx.) [Our Size 0#] Bottom Diameter: 1.3cm/0.51"", Top Diameter: 1.7cm/0.67"" (Approx.) [Our Size 1#] Bottom Diameter: 1.4cm/0.55"", Top Diameter: 1.9cm/0.75"" (Approx.) [Our Size 2#] Bottom Diameter: 1.5cm/0.59"", Top Diameter: 2cm/0.79"" (Approx.) [Our Size 3#] Bottom Diameter: 1.7cm/0.67"", Top Diameter: 2.3cm/0.91"" (Approx.) [Our Size 4#] Bottom Diameter: 1.9cm/0.75"", Top Diameter: 2.6cm/1.02"" (Approx.) [Our Size 5#] Bottom Diameter: 2.2cm/0.87"", Top Diameter: 2.9cm/1.14"" (Approx.) [Our Size 6#] Bottom Diameter: 2.5cm/0.98"", Top Diameter: 3.3cm/1.30"" (Approx.) [Our Size 7#] Bottom Diameter: 2.8cm/1.10"", Top Diameter: 3.7m/1.46"" (Approx.) [Our Size 8#] Bottom Diameter: 3.2cm/1.26"", Top Diameter: 4.2cm/1.65"" (Approx.) [Our Size 9#] Bottom Diameter: 3.7cm/1.46"", Top Diameter: 4.5cm/1.77"" (Approx.) [Our Size 10#] Bottom Diameter: 4.1cm/1.61"", Top Diameter: 5cm/1.97"" (Approx.) [Our Size 11#] Bottom Diameter: 4.6cm/1.81"", Top Diameter: 5.6cm/2.20"" (Approx.) [Our Size 12#] Bottom Diameter: 5.1cm/2.01"", Top Diameter: 6.2cm/2.44"" (Approx.) Notes: Due to differences in lighting and screen settings, the color of the project may be slightly different from the picture. Due to different manual measurements, allow for slight size differences. Package Includes: 1 x Rubber Stopper