FL - Contains fine-mesh pre-conditioned Activated Alumina to reduce fluorides below 0.5 ppm. Its capacity is up to 11,000 ppm with effluent levels below 0.2 ppm from 10 ppm feed. Note: high pH and high bicarbonate levels reduce the capacity - above 100 ppm bicarbonate, reduce by 50%; above 200 ppm, reduce by 75%. Also effectively removes low levels of arsenic. Typical life for a family of four with typical city water is one year. Fits industry-standard 10" slim-line housings. Not recommended by itself - it is best installed with a KDF/GAC cartridge following it (see Why Have a Fluoride Water Filter).