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 10x4.5 NOMINAL: 10” BB 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: 10” x 4.5”” PAC (Powdered Activated Carbon) water filters, compatible with CB-45-1001. SpiroPure SP-CBC-BB 10x4.5 CTO Coconut Shell Carbon 1 Micron Replacement Water Filter Cartridge