The Omnipure (Q5654-C100E) is a cation exchange softening cartridge which reduces hardness and scale deposits. 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 Hardness and Scale Deposits. This filter also uses C100E FDA grade softener resin.Omnipure Q5654-C100E Q-Series Water Softening Filter Specs:Dimensions: 2.5" W X 12" LFlow Rate: .5 GPMMaximum Pressure: 125 PSIGMaximum Temperature: 100 FService Life: 750 grains of hardnessFiltration Media: C100E FDA grade softener resinReduces: Hardness and Scale DepositsFitting Size: This Q-Series filter is a replacement filter and must be used with an existing Q-Series head. The Q-Series heads are available in 1/4" Quick-Connect fittings, 1/4" NPT female threads, or 3/8" NPT female threads.