8mm vial for hplc with pp cap Chrominex-aijiren Vials for HPLC Clear Glass Vial with Screw Cap ~ 2mL (1/2 Dram) –. Clear screw thread vial is designed with a continuous thread “CT” finish, permitting a positive seal, ideal for a variety of uses including laboratory or manufacturer’s use. with F217 (foam) lined Polypropylene Caps.