I'm not a luthier or guitar tech. I just need something cheap and cheerful to check the frets on new guitars to see which ones need to go to the tech for fretwork.
Does the job. There is a little tiny line protruding, on the longest side, where it looks like the machine cut started and finished. This isn't really a major issue, as long as you don't put that bit on the fret!
I was worried about it having sharp edges, as it's so cheap, but the edges are ever so slightly rounded off, so very little risk of cutting your fingers with these.
I'd recommend it, for the money.