These 125mL Pyrex® separatory funnels have PTFE No. 2 Product Standard stopcocks and inner and outer 14/20 ST joints. The PTFE plug fits into the micro-finish barrel. This funnel is also a replacement for organic chemistry kit No. 6949K. The plug also reduces freezing problems and grease contamination. For replacement glass ST stoppers, see Cat.No. 1-7650; for PTFE stopcock plugs, see Cat.No. 1-7681.