Removes calcium, magnesium, and other ionic impurities that harm steam sterilizers. Easy-to-set-up, quick-fitting connectors hook up directly to faucet. Fast: produces up to 4 liters of pure water per minute. No need to store containers of distilled water. Pura-lite notifies when it is time to install a new cartridge. No power required. Compact: fits on countertop or mounts to the wall for easy installation. 1-year warranty.