PTFE syringe filters are made of Polytetrafluoroethylene (PTFE) membrane and a polypropylene overmold housing. Available in 13 mm and 25 mm diameters and 0.22 μm and 0.45 μm pore sizes. 9mm Short Thread Caps with Septa Screw Caps with Septa for 8-425 Screw Neck Vial 10-425 Screw Caps with Septa 11mm Crimp Top Caps with Septa