8-425 2ml Screw Neck HPLC Autosampler Vial 2ml Autosampler Vials 8-425 neck finish represents a hplc vials &gc vials, the vials a diameter of 8 mm across the outside of the threads and a thread style of 425, Vials has clear and amber, Screw Cap in Lab most of the 2ml vials are 2*32mm.