Gucko Rubber Conical Gasket Stopper Ring No.7

Gucko Rubber Conical Gasket Stopper Ring No.7 is used in a laboratory setting to create a vacuum-tight seal between a glass funnel (like a Büchner funnel) and a filter flask during vacuum filtration, essentially acting as a gasket to prevent leaks when applying suction to the system; “No.7” refers to the size of the gasket, which should match the size of the flask and funnel it is used with.