So,
Since I use an infrared camera for my work often I hope I can help.
Emissivity and distance both heavily impact the reading on those thermometers. The detector in those small thermometers is only a handful of dots that detect. As you get further away the infrared light blurs and the limited detectors only sees an average temperature.
The laser is only supposed to show you what region is actually being measured. Accuracy is poor unless you are within a foot.
Emissivity is different for different materials. Aluminum has an emissivity of 0.3 while flat paint regardless of color is closer to 0.95. The higher the number the more Infrared radiation is emitted.
So I use the thermometer for comparison. If I need more precise temperature readings, I use a thermo couple on a fluke meter.
Please don’t interpret this to mean I discourage the IR thermometers. It’s the opposite. I hope to help everyone know how they are the most useful.
As for where they are manufactured? Sadly even the best cameras etc are not made in the US or Europe anymore. Buy the one that fits ur budget and get ur work done.