Whatman Syringe Filters, 50/pk PTFE, 25mm, 0.2um Call 800-548-1234. Whatman Puradisc disposable syringe filters provide a pure, particle-free filtrate. The 25-mm polypropylene (PP) housing has Luer slip and Luer lock connections. Box of 50. Part#: 64120. Whatman Syringe Filters, 50/pk PP, 25mm, 0.2um. Price: $216.75.