Purenex RO-5N 5 Stage Reverse Osmosis Undersink Water Filter System with 50 GPD Membrane and Storage Tank Thin film composite membrane 50 gallons per day, 95% fluoride removal NSF listed (3.2 gals) storage tank, rated for pressures to 100 psi; non-corrosive construction High quality filters for superior performance 5 micron spun, GAC pre-treatment cartridge, solid block carbon & carbon post filter