AQUA BLUE Premium Refrigerator Water Filter 3 Replacement Filter Cartidge | (Three Pack) Activated carbon adsorption technology can effectively filter impurities in water. Can remove most pollutants: reduce odors, chlorine, areas, rust, turbidity, heavy metals and harmful deposits. Easy to install and replace, no tools required. For filtering effect, replace every 6 months or 300 gallons. According to the characteristics of the product, replace the filter every six months or 200 gallons.