Do you have a problem with dew? There's a natural solution - Astro Zap Astro Strap Dew Heaters. Here's how it works... On one side of the AstroZap AstroStrap you find a sponge insulation. This keeps the warmth of the heating element directed towards your optics or appliances and saves energy while it keeps your gear moisture-free. Simply wrap the AstroZap AstroStrap Dew Heater element around your eyepiece or objective cell with the blue cloth side applied to where you want the heat. On the flip side of the AstroStrap, you'll find a black velcro closure. Just pull the AstroZap AstroStrap tight, press the connecting velcro tab to the back of the heater and the elastic holds it firmly in place. When running a full power, the AstroZap Dew Heater draws 0.35 amps and much less when operating in a normal mode. Each heater comes with a standard six-foot cord and phono-plug connector for 12-volt operation. But remember, the AstroZap AstroZap is just the heater and cord... You'll need a to supply the power. No worries! The AstroZap AstroStrap Dew Heater is compatible with Astrozap, Kendrick, Dew Buster, and Thousand Oaks Controllers. When you use an AstroZap AstroStrap the HEAT is on! AstroZap Product Number: 702