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.

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