K4300 vial is a direct replacement for Dionex # 055058, screw cap vial for AS-50 and AS-AP autosamplers. Our product is the same height and diameter as the OEM product. This product has a 0.012" pierce cap that is easily punctured by the sampling probe during analysis. The cap is molded of low density polyethylene. The vial is molded polypropylene and is used for 7mL samples.