Svbony SV192 Dew Heater 

• Protects optical equipment such as telescopes from fogging or freezing
• Fits 8" Newtonians, and 8" SCTs tightly, ~28" Length
• 3-speed regulator with medium weak heating mode; You can adjust the temperature according to different usage requirements;
• 5.5X2.1 female interface design; easy connected to various 12V power inputs;