The Microline S-1227RS is a reverse osmosis (RO) membrane for better tasting water in your home. RO filtration provides superior filtration, taking out a wide range of contaminants--including heavy metals, inorganics and volatile organics. Harmful chemicals that can damage your health or possibly cause cancer are trapped on the membrane surface, then swept away in the waste water. Reduce virtually all total dissolved solids, and set your mind at ease with reverse osmosis filtration.