10mm Screw Neck Vial with PP Cap for Autosampler -. 1. 10mm screw vials can be used on all common autosampler. 2. Standard narrow neck design for GC and HPLC. 3. 10mm wider opening for easy puncture. 4. 10mm PTFE/silicone septa, has excellent chemical inertness, acid and alkali resistance. 1.