2ml Screw Top Vials Zodiac has introduced Ultra finished HPLC vials made out of US Pharmacopeia type I borosilicate glass, with the brand name as Pro Clean. These chromatography vials are designed and engineered for trouble-free operation in most autosamplers, to give optimum performance with HPLC and LC/MS applications. These screw top vials that are nearly contaminant free, you can reduce the risk significantly by using vial products made specifically for these applications. These vials have a unique thread design that allows you to screw on the caps. This thread is much higher on the top of the vial allowing space between the shoulder of the vial and the bottom of the thread. Meeting the international standards in regarding quality and are compatible with Waters, Agilent and Shimadzu HPLC systems.