The Pentek U440 replacement filter uses ultrafiltration membrane technology to provide a physical barrier to particles, large dissolved molecules, most colloids, and impurities as small as 0.025 microns. To maximize membrane capacity and service life, a metered flushing cycle is utilized. The Pentek U440 replacement membrane employs hollow-fiber ultrafiltration membrane technology to reduce turbidity, particulates and cysts. The Pentek U440 membrane is sealed with double radial o-rings, minimizing the potential for leak paths. The Pentek U440 membrane/housing has quick-connect end caps which allow the membrane to easily be removed for cleaning or replacement. The Pentek U440 ultra filter membrane needs to be flushed on a schedule dependent on the quality of water being treated. The Pentek U440 Replacement Filter Module Membrane is the replacement membrane for the Pentek U440 Ultrafiltration System.