Ancnoble Auto-Refill Steel Solar Powered Water Dispenser for Pets, 12 by 11 by 7-Inch Auto water refill, drain and change to make sure there is always flash water for pets Made by solid galvanized steel, 10 inch diameter, 4 inch deep Solar-powered with no need of batteries, or power line Light sensor to make sure there is no water changing at night to save water There are 2, 4, 8, 24 hours interval time to choose from for water changing