Choose from a variety of 8mm Crimp Seals with septa to. Chat Now Get Price WISP™ 48-position autosampler vials PP caps Contains 4mL clear glass, screw-thread vials, 0.01in. thick white PTFE septa, and PP caps. Constructed of borosilicate glass. Screw-thread vials use 11 mm septa and 13-425 threaded screw-caps.