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

Works great at keeping the dew away! Lightweight and easy to pack; it lives in my astro kit year-round with a small battery. Troubleshooting: it's low draw means that SOME portable batteries will turn off because they don't think they're being used. If you think it's broken, try different batteries, or plug something else into the battery to increase the draw!

A simple item, keeps lens warm to avoid dew/condensation problems. Good Things: -Sort of elastic-y, seems to fit 50mm to bigger lens (see picture) -Will run all night on a large USB power brick, did not try with a small one -Has 3 power settings Where I live, cold is 35F, so I did not try it in the snow or where 'cold' is colder than that. Before using this I did have problems with lens condensation in situations where the camera/lens were outdoors overnight. This fixed that problem. Low worked for me (~40F) overnight. I did not try other settings. Did not use with 'star tracker'. Cannot speak to that, but I doubt that there would be problems. Bad Things: -None that I can think of

The product works good to keep my lens warm for long shoots outdoors in the cold and in the night. It does seem rather cheaply made, with some seams on it already ripped fresh out of the box.

Super cool. Works like its designed to. The clearest skys come at the expense of cold air, and this is mandatory.

I use these on the lowest setting for keeping my 2" telescope eyepieces from dewing up and they work great. They seem to draw about 0.7A @12V or about 8W when cycled ON. But they are only drawing power occasionally.

Works great!

Almost two years old now and still going strong.

All my astrophotography scopes are equipped with Neewer usb straps. I power them via an external usb hub that has a 12v 6amp supply dedicated to them but I have powered two directly from my Asiair Plus when needed. They are a high quality well built dew strap and have been running fine for some time now. A great value.

Ottima resa,3 diverse temperature. Alimentazione usb, perfetto per Celestron Nexstar 6SE

Size is perfect but it does not get warm even at high temperature Setting.its just a notch below Warm

Muy buen producto, ideal para tubos pequeños y teleobjetivos

Perfecto cumple su cometido todo ok

Seems like a well-made heater and does get good and warm based on human body temperature. Temperature Control: Single tactile mini PCB button cycles through 3 LED-lit heat levels. Temperature Feedback: Includes a NTC thermistor which may be used in control algorithm, or just for a high-temperature cutoff. (Don't know.) There is a 14-pin integrated circuit on an SMT circuit board. Good quality manufacturing techniques using surface-mounted components. Electrical Input: 5 V, 2 A = 10 W nominal. Actual measured voltage: 4.7 V Made in China. Note: Does not maintain previous setting after power interruption. This may cause issues depending on application. The maximum diameter with a full heating circumference is 7" diameter. This won't fit around my entire humoungous head, but it can be extended and fastened over 8" in diameter, leaving a gap between the end of the heating elements. This can be connected to a full-sized USB connector. Could be connected to an electromagnetic receiver or transmitter, to send or receive signals through brainwaves. Possibly entertainment value when combined with binaural beats. Please Note: this is not a recommended use for this product. Please only use it for keeping camera lenses anti-dewed.