But our commitment to quality does not stop there. Each certified vial is made from Clear, extreme high recovery, 16 mm cap size, write-on spot 30/pk 5188-2757 ... Clear vials, blue screw caps, PTFE/silicone/PTFE septa 100/pk 5182-0555 Clear vials with write-on spot, blue screw caps, PTFE/silicone/PTFE septa 100/pk 5182-0866 ...