If you are looking for some flask stoppers, then you miss our rubber stoppers. Simple in structure, very easy to use. Suitable for professional and personal use. Small and light, easy to take; strong sealing; good silicone stopper, safe and reliable. Features -Color:Black -Material:Rubber -Size:4.10X4.10X2.50cm/1.61X1.61X0.98in -Size:3.70X3.70X2.50cm/1.45X1.45X0.98in -Size:3.20X3.20X2.50cm/1.26X1.26X0.98in -Size:2.70X2.70X2.50cm/1.06X1.06X0.98in -Size:2.60X2.60X2.50cm/1.02X1.02X0.98in -Size:2.50X2.40X2.40cm/0.98X0.94X0.94in -Size:2.50X2.00X2.00cm/0.98X0.79X0.79in -Size:2.50X1.90X1.90cm/0.98X0.75X0.75in -Size:2.50X1.70X1.70cm/0.98X0.67X0.67in -Size:2.50X1.50X1.50cm/0.98X0.59X0.59in -Note:comes with 11 different sizes. -Perfect for chemical industry, medicine and other scientific researches use. -It can be used with the test tube. It is a necessary sealing rubber stopper for experiments. -These rubber stoppers are using a suitable shape design, easy to insert and pull. -Small and compact, easy to store and use, not taking up any space of home or laboratory. -Smooth and , will not do damage to the bottles or test tubes in laboratory. Package list: 5 x 000# Stoppers 2 x 00# Stoppers 2 x 0# Stoppers 2 x 1# Stoppers 2 # Stoppers 2 x 3# Stoppers 2 x 4# Stoppers 1 x 5# Stoppers 1 x 6# Stoppers 1 x 7# Stoppers 1 # Stoppers