SVBONY SV172 Dew Heater, Lens Warmer 240mm, Universal for Telescope Camera

Works well and low power usage

I bought several of these dew heaters for my telescopes and lens, and found them to be very well made, at a great value. They can be fitted snuggly around the tubes/eyepieces and remain fixed in place. Proper sizing [circumference range] for your intended use is critical, so make sure you purchase the correct size for your application [as they don't stretch (and shouldn't)] As a test, I tried strapping two units in-line to wrap a larger telescope tube and they worked great... just requires 2 USB ports. The included switch/temperature control is compact and very easy to operate. The nice little padded mesh travel/storage bags are a nice benefit too. I was skeptical that these 5v USB powered (vs typical 12v powered units), devices would be able to provide enough 'heat power' to defeat dew onset, but they work very well; and their quick/convenient USB plugs makes hookup (into 60W USB charging hub) quick -n- easy. They need just a bit more time to heat up as compared to older style 12v [higher amps] strip heaters, but they get the job done. Their value to benefit and build quailty is terrific, and I suspect that I should get multiple years use out of them.

works great at maintaining temperature. Nice quality.

I needed an eyepiece heater to combat the inevitable breathing induced fog that cursed my infrequent viewing nights...I am primarily a visual observer, and I have a few 2" eyepieces that plop into my dob for orgasmic stellar and planetary observations. Recently with the conjunction of Saturn and Jupiter, my target was way low on my horizon and was only getting worse as the days ticked off to the 21st...was out with my wife in early December and we kept breathing on the eyepiece and it was super frustrating, so I researched and bought this thingy. It works well and plugs right into my USB powerpack that I've had for years. This one worked, while another type of heater meant for a more expensive battery setup did not work with my powerpack and an adaptor cord to USB (returning the other one, cause it was just an experiment to see if it would work and it did not warm appreciably). I don't need a dew-not or dewzapper system, when I have something that works very well with my USB pack...you mileage may vary, especially if you intend to use a 12v power supply for other things and justify a $150 power distro system.

I was looking for lower priced dew heaters for my telescope and guidescope. I also wanted usb powered since I do not have a dedicated 12v system for managing dew heaters. For the price I went ahead and tried these and so far they have worked well on my Sharpstar 61 and Ioptron guide scope. I’m using them from a usb power bank and with the 3 adjustable power options they have worked fine for my environment. I’m in Texas so it hasn’t gotten really cold yet, but they work well in the current autumn weather. If you want a less expensive usb powered option, I would recommend these. Do make sure to measure your scope or lens and compare to the length of the heating element of the heater.

I woke up at 4am the other morning to view Saturn high in the sky with excellent seeing. I got an awesome view (the seeing conditions were perfect as in the air was perfectly still), but my eyepiece fogged up. I got this heater, and a few days later I got up at 4am again to look at Saturn again. This time the seeing was good but not perfect, but the heater did its job and the eyepiece didn't fog up.

I used this product to warm up the sides of an acrylic fish tank to stop condensation from forming and leading to mold. It worked great with the included temperature regulator, but the regulator automatically shuts it off after a certain period of time. I wanted it on constantly, so I plugged it in directly without the regulator. I got a little bit of deformed plastic on the fish tank after leaving it running it constantly for about 3 days. So, I guess I should have kept using the regulator! I'm leaving 5 stars because the quality was very solid and it looks like it would work great for its intended use on cameras. I also loved the velcro system, I was able to attach the lens warmer to something bigger than intended simply by buying a normal strip of velcro. I also liked that the regulator was a separate piece, gives more flexibility for use.

Had issues with dew on my guide scope during the winter, this solved it.

Well made, works without fail and recommended for value versus the big name brands...

Great product. Works as advertised. Usage depends on your camera, lens and the weather. Ensure you power it up with a good power supply.

Worked perfect for my 180 mak... stupid "light" you mean water bucket. 😆

Good job 👏

I’ve been using SVbony products since my SVbont telescope purchase, and this one matches/looks/works great on my SV550 scope