Ensures your Evolution RO1000™ runs more efficiently. Less filter changes and maintenance - every 7,500 gallons of purified water. Cleanable sediment filter is re-usable. Combination of KDF85 and KDF55 with earth-friendly catalytic carbon filter reduces chlorine, chloramines, iron, sulfur and heavy metals - great for city or well water. Highly recommended when using more than 150 gallons of purified water per week average.