Description Are you looking for a practical stopper for your experiment? Do you want a reliable test tube plug? If your answer is yes, please come and take a look at this product. This test tube stopper is made of good material, which has the long service life. It will meet your experiment sealing needs. Features - Color: White -Material:Silicone - Size: 3.30X1.70X1.70cm/1.30X0.67X0.67in -Specification:12-17mm -Suitable for test tubes, flasks and other laboratory equipment that need to be sealed. -Widely applied in laboratories, research institutes, universities and other places. -The silicone stoppers are small in size and light in weight, convenient to store and use. -There are enough bottle stoppers to meet your different needs. You can use it with confidence. -Fine workmanship premium silicone material, and good durability, can be used for a long time.Package list: 20 x Stoppers