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. Additional Details ------------------------------ Product description: 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.