These separatory funnels feature smooth tooled tips, large, white block letters, and large marking squares. Supplied with Teflon® stopcocks to eliminate freezing and lubricant contamination and to provide a precision fit within the barrel. The stopcock bores, body openings, and stems are carefully aligned for even liquid flow with fast cut-off. Made from borosilicate tubing with a low coefficient of expansion. Borosilicate tubing also provides uniform wall thickness resulting in the optimum balance between thermal shock resistance and mechanical strength.