HPLC filter vial with pre slit cap supplier--Lab Vials . HPLC filter vial with pre slit cap supplier. Materials of construction: pp chamber, PP plunger outer housing, borosilicate glass plunger inner storage vial, silicone septa with PTFE liner, PP cap. Vial Size: 2 x 32 mm. Pore Size: 0.22um and 0.45um. Capacity: Unfiltered sample chamber: 500