When it comes to metal detectors, I'm at best a beginner but the last one I owned wasn't as good as this one when it came to detecting anything below a few inches in the ground. With this metal detector, I'm able to detect almost a foot's depth in ground. Not to mention, this is fully waterproof and have been able to find things along the shore banks in lakes and small river banks near my home. Surprisingly, this is a lot more accurate than I thought it was going to be. The amount of things that I have found has been big to an antique spoon and few things that were bigger but then as small as what I later found out to be a small piece of gold. What I love about this detector is the accuracy and the fact that it doesn't weigh too much that it feels as though my arm is going to fall off. The sound on this was is clear, especially when it's detecting something and it can get fairly if you don't turn the volume down.

I use this for monitoring small spaces in our smoke duct and between floors. Should do a little bumper around the camera to protect it from heavy use
Quality seems good but I've only had it a few days.

I purchased this CO2 monitor mainly because of its compatibility with the Tuya app, which I already use to control my smart light bulbs and smoke alarms. The ability to connect all my smart devices together and set up a link that automatically triggers my smoke alarms in case of dangerous CO2 levels is fantastic.

Regarding privacy, I can only speak for the iOs version, and Tuya did request access to my location, local network, Bluetooth, and Homekit. However, I don't feel this is anything unusual. The location permission was only requested when I tried setting up a home/away routine, which I think is a reasonable tradeoff for the convenience this smart device provides. Overall, I'm happy with my purchase.

This monitor does what it’s supposed to do. I did test with with and smoke and it alarmed right away. Have it installed in our basement to detect any harmful gases. So far hasn’t alarmed or detected any gases which is great. Nice to know air quality.

I accidentally ordered two. They came charged. Did not require the 24 hour calibration cited in the manual. I put it by a window fan to calibrate for 10 minutes. Sequentially, they both settled at approx 405ppm CO2. I recently purchased another AQI meter from TempTop so I was able to compare pm2.5 to some extent.

I've only had these a couple days but I've closely monitored and corroborated the circumstances. All measurements between both units are effectively identical, no variance unaccounted for. The CO2 measurements proportionally increased based on quantity of occupants in my office, if the door was open/closed, central forced air ventilation (A/C system), and window fan. Most observed ranged have been between 400 and just over 1000, though intentionally breathing on it will exceed this.

The PM2.5 measurements correlate with the TempTop, though PM2.5 and PM10 jiggle up to 003 over the base reading, which is negligible. Because I purchased these to fill the CO2 gap the TempTop does not capture, I don't have much more to contribute in these readings yet.

The temperature and humidity are in line with all my other devices as well.

There was a review regarding them recalibrating on their own. This is an optional feature if you read the book, though I don't know why someone would want that to be recurring regularly.

I said I accidentally purchased two... I think I'll get more. Maybe one for me, but others as gifts. I think it's valuable to know the quality of air being respired, especially in places you spend the most time.

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Update:
I purchased a QuingPing monitor based on other reviews I read, largely because it esthetically enumerated the measurements I was most interested in, being Co2, PM, and VoC. This revealed that I absolutely needed to calibrate these units... I assumed when I started them and they hung at 500 for awhile, that was a calibration phase; Anyhow, after calibration they are coming congruent with the QuingPing. Even uncalibrated, bringing this unit to restaurants and my vehicle, etc still demonstrated increased Co2 and PM values, that even if the "floor" was high, was still valuable when taken relatively.

My opinion is that the Co2 alone is an excellent mechanism to measure ventilation in typical scenarios, and that can be used as an effective proxy for air quality generally. This assumes average room area, outdoor air quality, and no extraordinary sources of PM/VoCs like aerosols, flame (candles, gas appliances), or a operating workshop. For the budget minded, or entry level gifter, the Co2 only monitor would be good.

The construction of these are solid, even rugged, and the battery life has been at least adequate for my exploration. I appreciate the USB-C ecosystem. The color added to the screen, though it is static and never changing, makes it passable.

I'm probably going to move to QuingPing primarily, and use these as indicators suggested above (maybe in my car and/or kitchen). The QuingPing, while almost twice the cost, is quite featureful. It includes Wifi connectivity, with onboard and cloud telemetry logging, a nice touch screen and interface, is even more esthetic, and common home automation platform integration, etc. I'll probably settle for two QuingPing units, one in the bedroom and the other in my office. I'm still evaluating the accuracy before committing to a second unit, but it's looking promising.

 My wife has been having headaches recently over the past few months and I decided to see if elevated Co2 can be the cause. Well, I was surprised to see the high levels of CO2 build up in our house. Having a good quality monitor like MOES WIFI Air Quality Monitor CO2 Detector with temp is very useful!
I like that this monitor is able to switch from C to F because I use F temperature here in the USA. This also comes with a rechargeable lithium battery with a capacity of 2400 mAh which makes this great for when I go camping with my propane heater.
Carbon dioxide, or CO2, is a harmless gas in the atmosphere, but if its levels rise inside a home, it can cause health problems for the people who live there. People and animals exhale CO2 as a natural function of respiration, so CO2 levels can rise if a home is overcrowded and has insufficient air exchange with the outside. Soil capping is a process that can occur in houses built on old farm sites when damp weather causes the soil to expand and release gases into the home, including natural amounts of CO2. Inadequate air conditioning systems can also contribute to elevated CO2 levels. Another source of increased CO2 is the use of fossil fuels in the home--so it is very important to have the tools to monitor your situation and warn you if something is wrong.
Attached are some photos to have a closer look at device. This is USBC which is awesome! The quality of screen is bright and very easy to read in day or night time situations.

This is nice. Although I am not interested in the amount of humidity, I am interested in a Carbon Monoxide and Smoke Detector for our Airstream. We checked it out with the smoke and works and if the carbon monoxide alarm is as loud it will be great. It has a nice clear design and it is pleasing to look at.

I like how this is more modern than the traditional ones that hang on the wall and look like a smoke detector. This has a digital read out. Mine says all zeros, I assume it is accurate as I have a hand held unit also - that isn't going off. This was simple to turn on and charge. Does NOT come with a plug for the charging cable, only the cord that goes into a USB port.