SimPure high-efficiency RO Filter removes contaminants 0.0001 microns or greater in diamete. This tankless ro water filter system is equipped with SimPure special reverse osmosis membrane, so the TDS Removal Rate can reach up to 95%+, which is highly improved from under cabinet reverse osmosis systems. If the TDS of your tap water is between 0-200ppm, the filtered water will be close to 0ppm. https://www.simpurelife.com/products/under-sink-tankless-reverse-osmosis-system