Dec 08, 2021 · DX PTFE Syringe Filter, 0.22um, 4mm, 200/pk Available pore sizes are 0.10, 0.22um and 0.45um. Available diameters are 4mm, 13mm and 25mm. Compatible with nearly all solvents. High backpressure with aqueous solvents. The most universal filter. Dual-layered membrane. Certified DNAse/RNAse free and non-pyrogenic.