Sample Vials with unique thread design ensures consistent seal and can be reused, not volatile, easy to use 9mm Screw Thread Autosampler Vials are made of clear Type 1, Class A Borosilicate Glass with a writable label for sample identification. 2ml Clear autosampler vial,12mm Diameter, 32mm Height, 9-425 screw top, and included blue ABS Screw Cap