A 12" CTO-grade encapsulated 10-micron carbon block for chlorine and chemical reduction. This is the standard pre-filter for a Q Series reverse osmosis unit.

Manufacturer’s Recommended Life: 3000 gallons or 1 year. Suggested Use: Undersink filter, refrigerator filter, or pre or post filter for reverse osmosis unit. Works best with relatively sediment-free water. Sediment can shorten lifespan.