Great tool, you see them made by Euro tool companies like
Wiha and
Knipex. Not sure who made that particular unit.
I find they're vastly superior to the typical American "Millers" if you're stripping a lot of the same gauge wire.
If you look at them end-on they have sharpened, V-shaped notches in the tips.
Squeezing the handles brings the V's together, overlapping, which forms a sharp-edged, diamond shaped hole of variable size.
The knurled thumbscrew with the knurled lock nut sets the size of the diamond hole.
Set them so that they cut into the wire's insulation, just short of touching the conductor and you can strip all day without any nicks. (Or is that knickers...?
)
pc