Opaque, PTFE beakers.Rigid and non-porous with a smooth surface.Resist all chemicals except molten alkali metals and fluorine.Are an efficient substitute for platinum.

• 此类烧杯乃属不透明，硬质、无孔、平滑表面，几乎对所有的化学品皆有抗性的烧杯，惟对熔化之碱金属及氟较为敏感，是铂的良好取代品。