Vials "Screw Top" 10/20 ml Configured with pre-assembled PTFE/Silicone screw caps and SEPTA. Vials light glass with upper thread to be configured with screw cap (open or closed) and pre-assembled PTFE/Silicone septum. High pressure resistance. Guaranteed not to burst from pressure; Precision Screw Thread Insure Sealing; Eliminate Errors Due to