Silicone Cork For Filtration Flask can be used as the advanced and high-functionality closures made out of natural cork. Its main use is to seal gas and liquid. It allows the diffusion of miniature amounts of oxygen. It is specially made for filtration flask. The said cork is provided with a controlled porosity and allows for the delivery of reproducible quantities of oxygen. Silicone Cork For Filtration Flask is a natural and lightweight. This is extremely compressible and is highly abrasion resistant. It has low conductivity to heat, vibration and noise.