Caps, Screw Top, with White Silicone Rubber / White PTFE Septa, fitted in knurled phenolic, Black Caps. For use with 24-400mm threaded EPA Style vials. ND24 threads. BASIK Brand. 12/PK.
This cap can be used with EPA Style Screw Top Vials or can be used with heavy wall, Reaction Vials. Phenolic caps are used when higher temperature than polypropylene can withstand is required. Phenolic caps can be brittle and crack when subjected to excessive force when applying to the vial.