The Omnipure (Q5785) is a crystalline polyphosphate (slow dissolving) filter with 20 micron polyspun post filter. This filter features the optional Twist Tap in-head valve system, which automatically turns the supply water off when the body is disconnected from the head. This filter can be used in ice makers, refrigerators, beverage equipment, drinking fountains, under the sink systems, and reverse osmosis systems. This filter aids in the removal of Scale