Bosean BH-4M Portable Multi Gas Detector.
Measures CH4 (Methane), O2 (Oxygen), H2S (Hydrogen Sulfide), CO (Carbon Monoxide) levels typically for safety applications.
This unit is very modern with USB-C charging and a bright LCD display.
More info available here.
Pictures are of actual item.
Rating : 10/10
Like new. This unit was purchased new and used for < 1hr at a desk. This unit was purchased for a data logging application but cannot make measurements while plugged in.
Thanks for viewing!