Yup, yours looks legit.
Actually mx-4 is pretty good. Compared to noctua, it's way cheaper and the temperature difference would be like 2-3 degrees.
Same for thermal grizzly, but this one has a major drawback, it dries out at 80 degrees. MX-4 can do 150 degrees continuous use. Thermal grizzly is rly great if you're into sub-zero cooling.