20" x 4-1/2" BB Coconut Shell GAC + 5lbs KDF55

AF Series cartridges are double-open end cartridges that fit standard residential and industrial housings. Cartridges are available in 2-1/2" and 4-1/2" diameters and 5", 10" and 20" lengths. Using premium Resintech media and offering oversized cartridge cavities Features: Coconut Shell Granular Activated Carbon (GAC) cartridges with KDF 55 medium KDF 55 Media is for the reduction of chlorine and water-soluble heavy metals to the rated capacity of a specific filter cartridge. This media also controls scale, bacteria and algae, even in hot water due to its Bacteriostatic properties. Patented KDF medium consists of high purity copper-zinc granules KDF uses redox (exchange of electrons) to effectively reduce / remove contaminants.