Amphiro A1 Self Monitoring Water & Energy Smart Meter for Shower, amphiro-a1-s004, White/Blue Displays energy consumption, energy efficiency class, water temperature and water consumption Average savings of 440 kWh and 2245gallons of drinking water per household per year No batteries required - The device harvests its energy from the water flow Quick and easy installation without any tools; fits with handheld showerhead (1/2-inch threads) Manufactured in the Austria, materials approved for drinking water