The Erva heated bird bath is guaranteed to provide your birds with water down to -20 degrees F.!
Clamp mounted Heated Bird Bath is 60 watt thermostatically controlled. Some icing on the surface of the water is normal when temperatures are this low, especially if there is a breeze.
Your birdbath is not defective if ice begins to form around the rim.
Heated Bird Bath dish is 14” in diameter. It nests in a clamp mount gray granite ring. One year warranty.