Heated Birdbath for winter use. 20 inches in diameter and about 3 inches deep. Thermostatically controlled, only goes on when temperatures dip below freezing. Uses about the same electricity as a 150 watt light bulb. Mounts on any deck railing with included clamp. Will mount on a 2 x 6, 2 x 4, or smaller aluminum deck railing. Tips over for easy cleaning or adding fresh water. The birds love it! Not even a year old.