Now you'll never have to worry about your Rigel finder dewing over again! This U-shaped Telrad Dew Heater from Astrozap wraps securely over the viewing window and doesn't obstruct the view. When running a full power, the Astrozap Dew Heater draws 0.88 amps and much less when operating in a normal mode. The heater comes with a four-foot cord and aux-plug connector for 12 Volt operation. The Astrozap Rigel Dew Buster is just the heater and cord, therefore you will need a dew system controller to supply the power. No worries! The AstroZap AstroStrap Dew Heater is compatible with Astrozap, Kendrick, Dew Buster, Orion, and Thousand Oaks Controllers. When you use an Astrozap AstroStrap the HEAT is on! Product Number: AZ-222