The Omnipure Q5548 water filter is a calcite filter. Calcite is used for remineralization of soft, acidic, or low pH water. Replacement of the spent media bed is done quickly by detaching the filter body from a permanent head with a twist of the wrist. The new Q5548 water filter body is just as easily threaded into the head and the replacement is then complete. The Omnipure Q5548 water filter is very user-friendly and can be used in icemakers, refrigerators, beverage equipment, drinking fountains, undersink systems, and reverse osmosis systems.