The Culligan D-30A Advanced Drinking Water Cartridge provides refreshing drinking water by reducing chlorine, particulates, and bad taste. The D-30A works as a replacement cartridge for the Culligan US-550, US-600A, SY-2000, and SY-2100. The filter comes with a 0.5-micron (nominal) filtration and has a filter life of 12 months or 1000 gallons. Micron rating of 0.5 Filter life: up to 12 months or 1, 000 gallons Compatible with Culligan US-550, US-600A, SY-2000, & SY-2100 systems | Culligan D-30A Drinking Water Replacement Filter