Screw thread top vials are made of Borosilicate glass TYPE1. Especially be compatible with kinds of autosamplers, including Aijiren,Aijiren Technology, Varian,Shimadzu,and etc PTFE/Silicone septa are most popular for HPLC applications Clear and Amber vials with or without graduated writing area. Both pre-slit and non pre-slit caps are available