Stoppers are used with laboratory glassware such as flasks, mixing cylinders, and separatory funnels

Manufactured from 33 expansion, low extractable borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class A requirements.

Hollow, hexagonal head medium length Standard Taper stopper can be easily gripped, and may be set on the flattened top to avoid contamination of the ground surface.