Greenwood Products 03-40BTS723 40mL Clear VOA Vial Assembled w/Open Top Bonded T/S Septa {Heavy} Cap, Certified (Case of 72) Open top VOA vials meet or exceed EPA standards for volatile organic sampling. Open top vials may be used directly with many automated purge and trap instruments. Assembled with polypropylene caps with PTFE/Silicone Septa. Clear borosilicate glass vial designed for water