The TOTO ECOPOWER 0.5 GPM Controller for Bathroom Faucet Spout is designed for use with TOTO 0.5 GPM ECOPOWER spouts. The ECOPOWER faucet is ideal for high-traffic commercial spaces and provides an elegant water conservation solution. Powered by the force of running water, ECOPOWER hydro-turbines create an electrical current that is stored in rechargeable cells to power the Smart Sensor System of the faucet. The ECOPOWER faucet is highly efficient, replenishing power stores in as little as five uses daily. No external power source or battery replacement is necessary. The sensor is located at the tip of the spout to more accurately sense the hands of the user for touchless use. The on-demand system means that water flows only when needed and cannot be accidentally left running. When hands are present, the water will flow. When hands are removed, the water stops. Included: controller and mounting hardware. Purchased separately: ECOPOWER 0.5 GPM spout, water supply line for G1/2 connection, and optional mixing valve for water that is not pre-mixed.