VWR® Autosampler Vials, Inserts and Closures. Vial choices include: Crimp Top, Snap Top, and Screw top vials with a selection of 2mL, 12x32mm, 8mm Standard Opening Screw Thread Vials and Inserts. National Scientific Vials and Closures Catalog Lit No 20206 – VWR. Working volumes up to 1 .2mL reduction in total particle counts .