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 the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Rubber Stopper Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.