Full length stoppers, closed at bottom, with penny head Conform to ASTM Standard E 675

Stoppers are used with laboratory glassware such as flasks and separatory funnels. Sizes Standard Taper 10/30 through Standard Taper 19/38 are solid Manufactured from 33 expansion, low extractable borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class A requirements