20mm Crimp Headspace Vial Caps Msc207201 - Made-in-China.com. Product Description. 2.Available with amber or clear vial. 3.Available with 20ml or 10ml vial. 4.Magnetic Aluminum cap suit for CTC instrument. 6.Rounded or flat bottom profiles are available for accurate instrument compatibility. 7.6ml crimp top headspace vial with matched 20mm Aluminum & Magnetic Aluminum cap, 20mm PTFE/rubber septa.