Manufacturer Culligan D-20A Level 1 cartridge of granular activated carbon drinking water filter reduces chlorine, bad taste and odor. Has a large surface area for maximum absorption and has a filter life of up to 12 months or 1,000 liters. These numbers correspond filter cartridge model US-550 US-600 US-560 US-560K, CTR-210, SY-5167 and RO-3167-Fall In Reverse Osmosis System. The filter is NSF certified and guaranteed for 2 years. It also includes a sticker point of change and is recommended for the city and well water. D20 replacement filter cartridge reduces chlorine, bad taste and odor. Construction of granular activated carbon, high surface area for maximum absorption. Filter life up