Harley Benton Understring Radius Gauge

I wouldn't trust these radius gauges for very delicate and expensive instruments, I believe it won't take a lot for them to scratch any surface since their edges are super sharp.

I have experienced them catching on my fretboard because of the sharp edges, but luckily there wasn't a deep scratch.

But the gauges seems precise cut to the radius, so they'll be handy for setting up radius on the bridges.

It is a matter of, you get what you pay for. These are most likely stamped out and as such they have some very sharp edges with burs on them. I filed/sanded my set, so now they are very smooth. Also my set came with 2 12" for some reason..

Does the job, but can cut you're fretboard if you don't watch out.