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.