SVBONY SV172 Lens Warmer, 240mm Lens Heater Warmer Dew, 3 Gear Regulator Temperature USB Universal Dew Heater Strip for Telescope Camera

1) Used it to prevent condensation on my SVBONY SV165 Mini Guide Scope 30mm F4.2) just connected it to the ASIAIR PLUS and keeps the guide scope warm. Multiple days doing Astrophotography and no issues with lens fogging or condensation on them.3) build quality is great4) did not use the Three Position Thermostat5) cable length is sufficient6) overall I recommend this dew heater strip.

I use this on my guide scope and it works very well. Super easy to use. Does exactly what it should. For the money, the build quality is great.

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.

If you need a budget low wattage dew heater this is a fairly good choice. Mine draws 8-9watts at max and will raise the temp of the optics (on high) by around 3-4 degrees when it's fairly cold outside (35'F). But that's pretty much it's limit for sure. However when running off a power station (296wh) I wouldn't want anything pulling more than that. Well worth the money, and works even better obviously in warmer temperatures. It also fits my 80ED dew shield, although I don't think you could go much bigger.

I was very happy when I saw these. I'm a big user of USB 5v power for accessories on my telescopes.SVBONY has been improving a lot and these dew heaters looked to be a great addition to their line. Unlike most of the "blast furnaces" on the market, these don't get as hot which mean less chance of tube currents. Unfortunately, they have a lot of problems. From the start, they were very picky about the power supply. Using a USB power supply designed for computers and recharging, some of the controllers would turn off after a few seconds. I then tried them in a USB power strip running off of a 12v power supply and they seemed to have no problems. Since this is my scope power, I was happy. Within several weeks, the controllers stopped working. They would just show the ambient temp and not heat. Removing them, the dew strips would heat without getting "hot". That stopped a few weeks later. I bought three of these and use two on the mirror end of my 8" reflector. They were not 'kinked' or mistreated in any way. It's a shame they were a flop.SVBONY contacted me and after a few emails we got things ironed out. I made some suggestions to help improve both their product and the site description for the heaters. I hope that they take this to heart and come out with an improved product.

Nice kit includes a handy knit storage bag. The 3 level controller can be removed to plug the heater into the USB directly. The 400mm fits my 102mm SvBony perfectly on either the Dew shield or Main tube. Velcro closure is adequate to keep it on, and the overall quality is good.I have used these bands successfully below 20F. Remember 2 amps at 5 volts is only 10 watts at most, and depending on your scope, dew point, etc. results may vary.

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 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.