The simple structure of these silicone stoppers makes them easy to use, whether you are a scientist or conducting experiments . Small size and lightweight design make these stoppers easy to transport and store. Features -Color:Black -Material:Silicone -Size:1.67X1.67X1.25cm/0.66X0.66X0.49in -Size:0.75X0.55X0.55cm/0.29X0.22X0.22in -Size:1.55X1.55X1.23cm/0.61X0.61X0.48in -Size:1.64X1.64X1.27cm/0.64X0.64X0.50in -Size:2.00X2.00X1.40cm/0.79X0.79X0.55in -Size:1.60X1.60X1.28cm/0.63X0.63X0.50in -Diameter of plug part: 2.7mm 8mm 9mm 12mm 12.5mm 13.5mm - Owning the and break resistance ability, very practical, with excellent texture. - Suitable for salt bottle, , tubes, flasks, test tubes or other laboratory applications. -The silicone plugs are of simple design, easy to insert and remove, giving you convenience and ease of use. -The replacement plug designed is tight and can effectively prevent liquid or gas leakage. -Compact and lightweight, these silicone stoppers are easy to store and transport, good for using in both home and laboratory settings. Package list: 2 x silicone plugs 2.7mm 2 x silicone plugs 8mm 2 x silicone plugs 9mm 2 x silicone plugs 12mm 2 x silicone plugs 12.5mm 2 x silicone plugs 13.5mm