1)9mm screw vials can be used on all common autosampler . 2)"Short screw, long neck" to make the autosampler easier to capture. 3)9mm wider opening for easy punctur. 4)9mm PTFE/silicone septa, has excellent chemical inertness, acid and alkali resistance. 5)9mm screw blue open top pp caps. 1. 9mm Short Thread Vials ND9