These high-quality 11mm glass vials are 2 mL,12 x 32 mm and fit most brands of autosamplers. Made of superior quality 33 expansion borosilie clear Type 1,Class A or 51A Type 1,Class B Aijiren glass,they meet all requirements of US,EU,and JPN Pharmacopia. Easy-to-fill wide-neck opening vials require 6 mm diameter micro-inserts.