iSpring MS5 2.8" x 12" 500GPD DualFlow Reverse Osmosis Membrane, Fits RCS5T Advanced Dual-Flow 500GPD membrane saves 60% of water, with 1:1 drain to clean water ratio Low-pressure and high-capacity membrane for tankless direct ro output Fits iSpring light commercial RO system RCS5T Rejects wide spectrum of impurities down to .0001 micron Tolerance to a wide range of operating conditions