I bought one of those years ago, and couldn't really get anything out of it. I use a more conventional jeweler's loupe at 5-10X, less than 10 bucks on Amazon, it has small led illumination but you are just looking through a simple lense, not a microscope type. It allows you to see if there is anything clinging to the stylus, for cleaning purposes, but not much more.
I also have a couple of relatively cheap digital microscopes that I bought to experiment with SRA settings- very difficult to set up for a stable, focused image and I'm not sure they are powerful enough to determine if there is physical wear on the stylus.
I was hunting for an old fashioned stylus microscope for a while--not easy to find, haven't thought about it in a while.
I also have a couple of relatively cheap digital microscopes that I bought to experiment with SRA settings- very difficult to set up for a stable, focused image and I'm not sure they are powerful enough to determine if there is physical wear on the stylus.
I was hunting for an old fashioned stylus microscope for a while--not easy to find, haven't thought about it in a while.