It’s not worth the $$. The angles don’t seem to quite line up for all instruments. I spent a lot of time figuring it out and my instruments remained dull. I ended up getting a mini belt sander (bigger ones is what’s used to sharpen knives and stuff) on Amazon for under $50. I use the finest grit and even run some scrap metal across it to smooth it out a little more so it doesn’t chew up my tip. Then I put my loupes light on low (the reflection is too bright on high) and barely run the edge against the belt on whichever flat surface fits best for the instrument being sharpened.
All of this is for not if you don’t have a test stick.
Hope this helps