2ml Screw Top HPLC Vials. These 2ml wide-opening 9-425 screw neck vials are made with tightest dimensional tolerances to match leading brands like Aijiren, Waters, Thermo Fisher etc. Compatible polypropylene 9-425 open-top screw caps available with pre-inserted PTFE-Silicone septa. These chemically inert screw caps are made from virgin grade