Kimble kimax squibb separatory funnels funnel is supplied with a standard taper ground glass stopper and a ptfe stopcock lower stems have an id large enough 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 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