Screw Top Vials, Caps and Kits | Thermo Fisher . Screw thread vials & closures for HPLC, GC, MS appliions There’s a Thermo Scientific screw top vial for every HPLC, GC, MS instrument, appliion, and budget. Our screw top clear and aer glass vials and plastic screw top vials are available in 8mm, 9mm