These blue and white No. 9 PYREX® stoppers are made from linear high-density polyethylene and have closed bottoms to conform to Standard Taper stopper dimensions. The three rings on the plug provide an efficient seal. This improved design fully protects t

Borosilicate, with penny head Conforms to ASTM Standard E 675 Size Standard Taper 13 has solid plug; size Standard Taper 38 has recessed bottom Standard Taper designation indicates the approximate diameter of the ground zone at its widest (gauging) point.

These chemically resistant PYREX® keyhole stoppers are made from polytetrafluoroethylene (PTFE) and conform to Standard Taper stopper dimensions. The color-coded keys make sorting and selecting the correct size much faster and easier. These stoppers may be used in place of conventional glass…