SEOH Rubber Filter Aid for Filtration Flask Each;

This molded rubber filter disc is designed to support and seal in place a filter crucible or a funnel in the neck of a flask. Inside Diameter of the socket at the top is 32mm, and the outside diameter of the disc is 76mm. The bottom of the disc is flat to seal tightly against the lip of the flask. These are also useful for holding your round bottom flasks in place. These are sold by the each and brand new.