1activated carbon filter for automatic circulation type water supply replacement * 8 pieces set. It is recommended that the filter exchange one piece a month, set for about eight months. Size: L = 12.7 cm 2 exchange resin: Magnesium and calcium in water are removed, and it is made into cat-friendly water (soft water) whose hardness is lowered. High performance activated carbon: It absorbs odor and bacteria. 3 exchange resin: Magnesium and calcium in water are removed, and it is made into cat-friendly water (soft water) whose hardness is lowered. High performance activated carbon: It absorbs odor and bacteria. 4When cleaning the filter, please do not use detergent, please rinse off the surface dirt with water. When replacing the filter, be sure to clean the parts of the water supply unit to ensure cleanliness. 5The direction of installation of activated carbon filter is one direction only.