The Cal Pond vent is a versatile product that can be used during all four seasons in different applications. The pond vent with 10 watt EggLite installed will allow gases to escape from the pond once it has frozen over During severe winters, additional EggLites may be added to the vent by simply hanging them on the light holder. EggLites can be used in or out of water but transformer can not be immersed in water. Use during winter months to vent your pond Use the EggLite the rest of the year in your pond or for landscape lighting The floating ring on the vent can be used as a feeding ring Comes Complete with Vent, EggLite, EggLite Extension Cord, and EggLite Floater. THIS ONE DOES NOT SINK!!