NanoCeram® Pleated 4.5" x 10" Filter is an exceptionally unique filter with an absolute rating of 0.2 microns while maintaining high flow rates comparable to 3 micron pleated filters. Using a technological advancement in water filtration that has been used by NASA, U.S. Air Force, Toyota and many others for a performance in filtration that produces incredible results and cost savings for a broad range of particles down to 0.2 microns.