The Omnipure (Q5655) is a DI water 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 salt and TDS (Total Dissolved Solids) from your water.Omnipure Q5655 Deionization Water Filter Specs:Dimensions: 2.5" W X 12" LFitting 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.