Economic Choice Syringe Filters are available in a variety of sizes and membrane types to meet any application need. Choice Polypropylene (PP) Syringe Filters 0.2 µm, 25 mm, 100 Pk. Choice Polypropylene (PP) Syringe Filters 0.45 µm, 25 mm, 100 Pk. Choice Polypropylene (PP) Syringe Filters 0.2 µm, 13 mm, 100 Pk.