Detection method for PM: la-ser scattering, Detection temperature: -10°C~50°C, Display method: 4.3 Inch LCD screen display, Flow range: 180 L/min, Storage temperature: -10°C~60°C, Concentration unit for PM: ug/m3, Relative humidity: 20%~85%, Concentration unit for CO2: PPM, Concentration unit for TVOC: mg/m3, Material：ABS, Charging method: DC5V Micro USB, Item size: 145 * 97.2 * 78mm / 5.7 * 3.8 * 3.1in, Atmospheric pressure: 86Kpa-106Kpa, Package weight: 460g / 1.0lb, Item weight: 235g / 8.3ounce, Detection method for CO2: Infrared (NDIR), Package size: 180 * 170 * 90mm / 7.1 * 6.7 * 3.5in, Battery: 1 * lithium battery / 3000mAh(included), Sampling time: 1.5 seconds, Concentration unit for HCHO: mg/m3, Pixel: 480X270 pixels.
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Updated:
Banggood
Warehouse in China.
Link: DM72B-wifi Air Quality Detector
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Additional Banggood coupons:
1. First page
2. Second page
Price history and price alert
Do you need price history chart (for all/most countries) for DM72B-wifi Air Quality Detector? There we go. The lowest price was: $79.99.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).