Screw Thread Cap & Septa of 13-425 Screw Top Vial, Wide opening [CHROMINEX] Red PTFE/White silicone septa + Black cap closed top, for 4ml 13-425 screw top glass vial, 100/pk Part Number: CRX2004-6031 Specification: Thread type : 13mm thread Material : PP, Cap Color : Black & White Septa Material : PTFE