Used for optimizing & prolonging the battery life of a dew heater, Celestron Smart Dew Heater Controller 2x gathers & analyzes information in real-time to warm your optics. It helps prevent the formation of dew & can control two dew heaters simultaneously. An additional 12 VDC output port can be used to power another 12V device & works seamlessly with Dew Heater Rings.