According to different material, the 20mm crimp headspace vial can be divided into two types. One is domestic borosilicate, the other one is USP type1. Different material can meet the different of requirement of customers. 10ml & 20ml crimp top ND20 headspace vial with matched 20mm Aluminum & Magnetic Aluminum cap, 20mm PTFE/rubber septa, so please choose suit crimp headspace vial for your lab.