Our patented vial and cap design incorporates pressure-relief Range of Sample Vials and Caps - SCION Instruments Vial, Screw Top Headspace, 20mL Clear Glass 22.5*75mm. 100pcs/pk. 41311013, Cap, Open Top Metal Screw, (8mm hole), 18mm Silver Color with 17.5mm Blue PTFE/White Magnetic Caps - SeptaSource