Sediment Filter 5 microns Carbon Block Filter VOC Filter 50 GPD High Rejection Membrane Compatible filters for WP4V-50 WP4V-50 Compatible Reverse Osmosis Filters Includes: One 50 GPD Membrane, replacement for part 560018 One 10" 5 micron sediment filter, replacement for part 104017, NSF Rated One 10" Carbon Block 5 micron filter, replacement for part 101009, NSF Rated One VOC Carbon Plus post filter, replacement for part 101013, NSF Rated High Rejection membrane is a complete fit and function replacement for OEM Reverse Osmosis Membrane 560018. It utilizes an internal check valve, considered superior to check valves typically placed in the elbow of the system. A RO system with a faulty check valve will become less efficient by running constantly. By placing the check valve in to the membrane, you are assured constant efficient performance due to the periodic replacement of this critical component of the RO system. The element is manufactured from a cast thin film semi-permeable membrane capable of 97% stabilized salt rejection. All parts marked "replacement" or "equivalent" are not affiliated with the original manufacturer, part numbers and names are used for cross reference only.