Kimble kimax separatory funnels funnel is supplied with a standard taper ground glass stopper and an autoclavable ptfe stopcock plug lower stems have an id large enough so that a column of liquid will &”break”; with the stopcock closed, thereby giving a more complete separation and eliminating the necessity of emptying the funnel pear-shaped replacement ground glass stopper is 805100 designed from astm specification e1096, type iv requirements manufactured from 33 expansion, low extractable borosilicate glass conforming to usp type i and astm e438, type i, class a requirements. Warning: this product can expose you to chemicals including tetrafluoroethylene, which are known to the state of california to cause cancer. Prop 65 warning