1 MICRON RATING: With a nominal filtration rating of 1 micron, our quality NSF Carbon filter reduces fine sediment particles and chlorine taste & odor from tap water 20x2.5 NOMINAL: 20" slim filter made with CTO coconut shell carbon filter media NSF CERTIFIED: This filter cartridge is tested and certified by NSF International to NSF/ANSI Standard 42 for material requirements only QUALITY REPLACEMENT: 20” x 2.5” PAC (Powdered Activated Carbon) water filters, compatible with CB-25-2001 SpiroPure SP-CBC-20 20x2.5 CTO Coconut Shell Carbon 1 Micron Replacement Water Filter Cartridge