In order to secure the samples when they are in laboratory tubes or flasks, you need to cover it with an item that you can easily place in the tubes mouth. This item can be a laboratory rubber. These disposable items are very common tools in chemistry laboratories with flasks and test tubes. As the rest of the laboratory ware, stoppers are a fundamental and important item when it comes to sample storage and lab organization. Can you imagine having a sample laying around without any kind of protection?
These stoppers come in up to 16 different sizes for each container there is available in the market. A rubber stopper is a small, tapered plug used to seal the openings of test tubes, flasks and other laboratory glassware. Stoppers made of cork are also available for this purpose. However, rubber stoppers are preferable for applications that require a tighter seal or a greater degree of chemical resistance.