Polytetrafluoroethylene PTFE Syringe Filters, Hydrophilic, 0.22um, 4mm, Luer-Lok/Luer Slip, Sterile, 100 per pack, SF18245. Regular Price: $156.40. Price $136.00. Add To Cart. PTFE Syringe Filters,Hydrophilic, 0.22 um, 4mm, Luer-Lok/Luer Slip, Nonsterile, 200 per pack, SF17506. Regular Price: $203.41.