Brio Compact RO System Built in TDS meter (batteries included) TDS = Total Disolved Solids That tells you when its time to change the filter Sleek Housing That Encases the Reverse Osmosis Filtration System, and 2.2 Gallon Bladder Tank 50 GPD TFC Membrane Coupled with a 2.2 Gallon Storage Tank Provides All the Drinking Water You'll Need, (Yes even large families) Comes with European Faucet, Filters, and All Hardware & Accessories Needed to Install Fits Conveniently Under Any Sink, Easy to Maintain. No Tools Required for Replacements, All in One System.