Eliminates toxic gases from fish ponds during winter without the energy costs and harmful side effects of other products. While other breathers waste energy to maintain a hole in the ice, the revolutionary Pond Breather is designed to freeze into ice and circulate water above ice layer to exchange gas. Each day, Pond Breather exposes 4000 times the water surface area to the atmosphere than other pond breathers, yet requires only 40 Watts. U.S.A.