Caps for 4 mL Vials - Screw Caps | Sigma-Aldrich. Product # Description. Add to Cart. 854987: Assembled screw cap with hole and TFE/rubber septum black polypropylene hole cap, 13-425 thread, PTFE/red rubber septum, for use with 4 mL vials with 13-425 thread, pkg of 100 ea . hplc vial pp cap, hplc vial pp cap Suppliers and