Headspace Vials, Caps and Kits | Aijiren Tech Scientific 20mm Clear Headspace Crimp Vial, Beveled Edge, Round Base (C4020-2) Silver Pressure Release Crimp Cap, 7.5mm hole (C4020-32AP) Tan PTFE/White Silicone. 1000. 20-HSVST201-CP. 18mm Clear Headspace 20mL Screw Vial, Round Bottom, (20-HSV) Silver Steel Screw Cap, 8mm hole (18-MSCST201) 18mm Blue Silicone/ Natural PTFE. 125.