Stoppers are used with laboratory glassware such as flasks and separatory funnels.
- PTFE has excellent chemical resistance and resists freezing in ground glass joints
- Remove the colored polyethylene handle from the PTFE stopper before cleaning or exposing to temperatures above 80 °C
- Stoppers of sizes 9 through 22 are solid, and sizes 32 through 38 are hollow
- Designed from ASTM Specification E675