The media could not be loaded. If you are wondering if this thermal monocular from GoYoJo works, well yes - it does.

I have another thermal optic that has a bit more function and resolution, but it also costs 3 times what this one does!

This monocular is simple to use. The menu and interface can be learned relatively quickly.
This fits nicely in the hand and feels good as far as eye relief. There's some adjustment there as well to get a clear picture.
I got good battery life so far. But I cannot recall the specs of the battery. I would suggest getting something rechargeable, or two, if you plan on extended use. Like a night predator hunt or similar.

I won't go into all the specifications and such. You can see them on the listing and they are as advertised. The important thing to know is that they fit this device well and are really good for the price point. It really doesn't leave a lot out. Great monocular for a first entry into thermal.

6 color pallets to choose from, you'll find one you like best. They all worked fine and I've included some photos. 3 levels of zoon as well, I'll refer to the pics and the distance below.
Multiple reticules to choose from as well. Lots of good and useful features.

Regarding the pictures.
The green/shimmer pic is a barn about 100 yards out.
The person, and a running tractor, is about 45 yards - various zooms were used.
The 4 or 5 red dots (Red hot setting) are horses at about 350 yards out. Hopefully that gives you and idea of it's power and what it looks like in "view".

Oh, it'll save pics and videos internally and you can hook it up via included USB to download. I do not see a place to add a micro SD card, which I though was unusual. But again, at the price, it makes sense to not have this particular feature. So this, and maybe the battery not being rechargeable, are the only real drawbacks I might note. But minor stuff really, nice and feature filled thermal at a great price.

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As my title said, I'm new to thermal optics so I may not be the most qualified to tell you if this thing is a good value. However, that said, I'm happy with it so far. I'll be going on a hog hunt within the next couple months and also plan to coyote hunt with it as well. I'll come back to this review with other thoughts after that.

I've toyed with a lot of the settings and color palettes to feel pretty comfortable. The manual says the focus on the G210 is fixed but the G215 (15mm) is manual focus. The battery is a rechargeable 18650 and it's able to charge via the USB-C port which also allows for connection to computer to transfer images. The manual is decently laid out and seems to do a good job giving functions and what settings do.

For $400 it seems to be a decent device and gives you a tremendous advantage. You can look for hot and cool spots in your house or other applications to fix leaks/gaps. Tracking a wounded animal or searching for a lost/missing person. And, of course, hunting applications for nuisance animals.

A couple other reviews say they couldn't find an app to pair with it. It does exist on Google Play. I searched Thermal imaging, click the button that says New and it should pop right up and show GOYOJO. I have a Samsung S21 5G with Android 14. I turned Wi-Fi on within the monocular's settings and connected my phone. It eventually paired with the app long enough to get a couple screenshots to show it "worked". Once I moved around with the monocular to find other things, it disconnected with the app. Then later the monocular WiFi disconnected. Not a reliable connection and doesn't seem worth fooling with unless they resolve the issues within the app.

Pictures:
Truck (next door) and house (~75 yards away) were with my phone looking in the monocular.
Boy and dog screenshots of app.
Handprint on wall and me looking in mirror were transferred from the monocular.
Various pictures of animals with yardage and magnification.

This thermal imaging monoscope is well built and the electronics are top notch. The construction of the device itself feels very good and solid. It certainly gives me confidence that it is built to last and will hold up to the rigors of being used outdoors in the field. Of course, it is still an electronic device, so I will do my best to handle it with care. For function, the electronics are pretty amazing. This device effectively produces thermal images of warm bodied animals. I have to admit, it works better than I expected. The images are bright and clear. Not fuzzy shapes that are difficult to size-up. I really appreciate the color options. With 6 choices there is lots of flexibility to find what works best depending upon the conditions. My favorite is "Red Hot." It gives great definition to the warm object and it really pops out. The "Rainbow" is nice too and "Black Hot" gives a more realistic image, you just lose the pop. With the other settings, the living objects really jump out so you can't miss them. The zoom is very helpful, but I would have preferred a wide-angle option. The unit is compact and fits nicely in my hand and it is easy to hold steady and the eye cup is comfortable. Another nice feature is the App that allows you to display the image on a cell phone. It works great on my Android platform phone. Set-up was a snap. This thermal imaging monoscope also stores images so you can keep a record of important and interesting encounters. Transferring the photos to a PC is simple. All I have to do is plug the USB cord into my computer and transfer the photos over. The monoscope shows up as a USB drive. No special software was needed, it came right up. They have included a nice case to protect the device and make it easy to transport. It recharges using a standard USB power supply and a USB-C cord. Overall, this device expands the possibilities for exploring the natural world outdoors and I am very happy with it. It is going to be a lot of fun and, certainly, very helpful. I love the way it performs.

This thermal scope narrowly missed being available for use during the recent deer season in Maryland. It has the potential to significantly simplify the tracking of elusive game. The image quality is exceptional, although some fuzziness may occur when zooming in. From my backyard, I can easily discern raccoons, deer, and neighborhood cats concealed within the brush.

The construction appears robust thus far. However, the buttons on top are somewhat stiff, making menu navigation slightly challenging. This thermal scope offers the capability to capture both photos and videos, which is a valuable feature. A microSD card is conveniently included with the scope, which also comes in a high-quality case.

One enhancement I would suggest for this thermal scope is the incorporation of a temperature display feature, similar to my FLIR camera. While I acknowledge that my FLIR camera is considerably more expensive than this thermal scope, the inclusion of this feature would have been a significant advantage. Overall, this is an excellent thermal scope.

The media could not be loaded. # Physical construction
The device fits well in hand and feels sturdy. The buttons have a good positive click and are weather sealed. For transport a carry case is included, which has some space to store accessories.
When comparing this to a smartphone dongle thermal camera there are obvious advantages to the monocular form factor. Firstly this is much tougher. It will survive a drop. A phone with a camera sticking out of it won't. Secondly, having an eyepiece is a really big advantage, in the daytime you aren't competing with screen glare and at night time the light of a screen doesn't give away your location.
The GOYOJO eyepiece is good, it's bright and at 800x600 pixels it looks sharp. The viewfinder diopter has a huge range of adjustment allowing you to place the apparent distance of the image quite close or almost infinity. This range of adjustment should be really helpful for people who wear glasses.
The lens cap is rubber and fits securely. It is retained on a string to make it hard to lose. The string is long enough you can easily hold it and prevent it bouncing around while you move, again just very nicely thought out little details on this product. There is also an adjustable wrist tether to prevent you dropping the device.
On the bottom there is a standard ¼ inch tripod mount which is compatible with almost any tripod or monopod. When unmounted the device balances well on it's nose making it easy to place down and bring up to a viewing position which is a nice touch.

# Image quality
The sensor is 256x192 pixels and runs at 25Hz. There is no latency and the image feels very "live" through the viewfinder. The sensor is paired with quite a large and fast lens making it quite sensitive for its size. The sensor does not need to recalibrate every couple of seconds like the Seek Thermal devices and is much higher resolution than the FLIR ones in the same price range.
I have the 10mm model. The included carry case has a little extra space cut out so you can tell the 15mm version is about 5mm longer (funny that).
As for color palettes the device has all the major palettes you'd expect in a thermal camera. Classic "Iron Red" being the most visually appealing and "Black Hot" being the most useful in my opinion. You also get "Rainbow", "White Hot", etc, etc.
The menus on the camera also allow adjustment of image brightness and contrast. The default brightness is about one click too high for my liking but this is very easy to adjust.
There are also scene modes which I haven't quite figured out yet. They appear to fine tune the image for different situations.

# Sample images
I've included a few photos taken with the device: cat tax, power poles, a fence in the sunlight, and some photos of the device and my reviewing process, and a screenshot of the app. The video combines a shot of a fast moving fan to show the framerate and two others of spotting and approaching a rabbit from 200ft away. Of particular interest to me is the range you can identify such a small animal at and how easy it is to see the rabbit while it is inside a hedge and completely invisible to the naked eye. The device does not have a microphone and videos have no sound.

# Bonus features
This thing has a freakin laser beam. It can project a red dot which is pretty accurately aligned with the center point on the screen. This allows you to make sure you are looking at the right spot even if there is no thermal contrast. Nice!

# Battery life
The battery provided is a protected button top 18650 battery 3200mAh from ZLY. Protected means that it has an integral over discharge board in the battery. These are the same kind you would use in a high performance flashlight and are readily available if you want to carry a spare or two. But you probably don't need to, keep reading!
Powered off the device draws less than 4.4 microamps. This is far below the self discharge level of lithium batteries so it's effectively zero. (If you had a magic battery which had no self discharge you'd have to swap it out once every 83 years to keep the clock in this thing going)
Powered up it's drawing 294mA on average with occasional spikes to 400mA when it moves the shutter. This should result in 10 hours battery life with the included battery! Conveniently it doesn't lose settings or the clock value when changing batteries so it's painless to swap if you manage to run one flat.
Turning on additional features does increase the battery draw somewhat. WiFi adds 100mA, the laser adds 20mA, recording a video adds 30mA, if you turn the screen off by short pressing the power button you save 15mA. Really though none of this matters the runtime is excellent even if you turn everything on.
Charging wise the device charges whatever battery is installed when plugged into USB (C). You can also run the device while plugged in if you need even more endurance.

# App and WiFi
No permissions needed for the app! This does however mean you need to connect to the WiFi network the device broadcasts manually. But this is easy. When turning on WiFi on the device it will display the SSID and Password on screen. These stay constant until you choose to change them so typing these out is a one time deal. If you are on Android you'll see the "no internet connection available" prompt after connecting the first time. Select "always stay connected" and your phone won't prompt you any more about it. From there return to the app and hit "scan".
The video feed has surprisingly little latency. Approximately 50ms by my estimation. The image quality over WiFi is just as good as through the viewfinder.
WiFi range is pretty good at least 30 feet with no issues. Plenty of distance to allow you to put the device somewhere you wouldn't want your head to be while you monitor from a safe or warm location.

# Improvements
Minor but I'd like to see a setting to keep WiFi on both at startup. The manual notes WiFi is disabled at startup to avoid wasting power. Reasonable! But with battery life as good as this I think it's fine to let the user spend that battery how they see fit especially when there is an indicator showing the WiFi state.

# Conclusion
This is a great device, it has none of the usability issues you might be worried about if you thought this device was simply too cheap to be true. If you are buying it for hunting I think the 15mm version is going to be worth the price difference but even with the 10mm lens you can easily see a rabbit at 200 ft in pitch black. Definitely a good buy!