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.