Intelligent Temperature Control: This astronomical telescope dew heater strap features intelligent temperature regulation for faster, more even heat distribution across your optical devices. The active heating maintains an optimal temperature to prevent condensation, enabling clearer sky observations and astrophotography even in humid conditions. Wide Compatibility: Fits optical devices with objective diameters 65 mm to 300 mm. This anti-condensation strap works effectively with telescopes, camera lenses, birdwatching optics, and guide scopes. Available in sizes from 33050 mm for 65 mm objectives to 108050 mm for 300 mm objectives; choose the size that fits your equipment. Premium Construction: Made from high-quality polyester, this dew heater strap delivers durable performance while remaining flexible enough to wrap around different optical instruments. The thoughtful design includes a secure mounting system that holds the heater in place during your observations. Easy Power Connection: Simply connect via the DC5521 jack to any portable 12V power supply (not included) to activate the heating element. This convenient power option makes the dew strap suitable for remote observing locations where traditional power sources may not be available. Typical uses: prevent dew on telescope lenses and camera optics during humid nights; field astronomy sessions requiring reliable condensation control; dew protection for birdwatching or guiding setups in damp environments.