Create your own DIY Dew Heater with these simple tips - Sky & Telescope
Amazon.com : NEEWER USB Lens Heater, 12"/300mm Lens Warmer for DSLR Camera and Telescope, 3 Temperature Regulator Settings, Dew Heater Strip Prevents Dew, Fog & Condensation for Telescope Camera Astrophotography : Electronics
Dew Heater Ring - 8" | Celestron
Obsession Telescopes / Learning Center / Dew heater installation instructions
How can I stop dew forming on my telescope? | BBC Sky at Night Magazine
Dew Heaters for Astrophotography - Keep Your Telescope or Lens Dry