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:1.60X1.60X1.28cm/0.63X0.63X0.50in -Size:1.90X1.90X1.40cm/0.75X0.75X0.55in -Size:1.80X1.80X1.30cm/0.71X0.71X0.51in -Size:5.60X5.60X5.30cm/2.20X2.20X2.08in -Size:1.46X1.46X1.14cm/0.57X0.57X0.45in -Size:1.30X1.30X1.16cm/0.51X0.51X0.46in -Size:0.75X0.55X0.55cm/0.29X0.22X0.22in -The diameter of plug in part: 2.7mm 6mm 7mm 7.5mm 10mm 11mm 12.5mm - Made of silicone which features with stability and durability, very hard and smooth for usage. - 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. - Suitable for a wide range of items such as , bottles, and more. Package list: 2 x silicone plugs 2.7mm 2 x silicone plugs 6mm 2 x silicone plugs 7mm 2 x silicone plugs 7.5mm 2 x silicone plugs 10mm 2 x silicone plugs 11mm 2 x silicone plugs 12.5mm