for Camera Lens less than 80mm in Diameter

After a fogging incident on my 14mm the other night, I thought I would give a lens warmer a try. It worked well. For less then $20, problems solved. Used my BLUETTI EB 55 as power supply, but a smaller 10,000 amp power supply would have worked fine.

Astronomy. New to the hobby... and I am so glad these work as well as they do;-) Anyone who stares through a telescope on a winter night would understand. No drama, just plug it in and does the job nicely. Comes with a nice bag (some don't, I have others), has a nice cord that is easy to manage when cold. And the cord has been long enough to work fine for my needs (8"dob with a battery at it's base). I leave it on all night. In the beginning I checked the temperature regularly but now have just settled in to taking it for granted (sigh of relief)

I use this when doing nightscape photography and it does a great job of keeping the dew from forming on my lens. It has low, medium and high settings and so far I’ve only had to use medium. I power it with a usb battery bank. (Not included) Comes with a pouch that’s perfect for storing hit and the battery together.

Functions well in terms of its core purpose to keep your lens warm and condensation-free. The ergonomics of the two switches is poorly executed though. Each teeny tiny button is very difficult to engage. And the labeling of the buttons is very hard to see. I encourage a re-design of the controller. Make it 25% larger with better tactile feel.

Work as expected

I waited a while to write this to make sure I put it through its paces first. It works and does great. It makes a huge difference when doing any night shooting. This is an extremely useful piece of kit that has earned its spot in my small bag (an accomplishment for me).

After using this 4 or 5 times, the heater stopped working. When I went to the Support Page provided on Amazon, I was presented with a 404 error page. Ie: No support what so ever. I don't recommend buying this product. I have found it to be a waste of money.

Keeps the lens warm like it should

Fits my 61mm refractor nicely. The temperature control feels nice and the cable is very soft even in cold temperatures which i like. Heat level at high settings feels very warm and kept my optics dew free all night.

As an astrophotographer lens dew is an issue when shooting the night sky. I purchased 4 of these in the spring and use them regular. Temperature is controlled with a button press for 3 setting. I typically use a low setting for mild dew, when it gets heavier I switch to a High or medium. One thing to remember is that it takes a 3 second press on the temperature control to turn them on. I paired these with a cheap 10,000 mAh power band and the bands keep the lens warm all night long.

The instruction print is a bit small. To turn on hold the button for about two seconds. What's nice: it's long, and it comes in a nice pouch. Con: It may be just me, but I prefer my cables to be modular, this isn't.

It's cold in Manitoba, this lens heater did the trick by being able to stay out longer.

I purchased this product as a hummingbird feeder heater to prevent the nectar from freezing in a rare cold snap in BC