1.5ml 8-425 Screw Neck Glass Sample Vials. Glass Vials Lab 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 12*32mm Autosampler Hplc Vials &gc vials are available in a variety of neck finishes and opening diameters.