How bad is this cheap laser power meter_ _ HWLPM Mini 10W vs. Sanwu Tracer 20W

Does a cheap laser power meter even work? Is it precise enough to be usable? In this video, I test the cheapest power meter I have found for sale and compare it to a much more expensive one. I will use lasers of different colors and optical power outputs. Will the cheap one give the same reading as the expensive one? Let's find out!