These pencil sharpeners are made by the German school and office manufacturing company Kum and have special diameters for triangular and hexagonal pencils. Each sharpener has both an 8 mm and a 10 mm pencil sharpener hole.
Very sharp blades and makes a wonderful crisp pencil point.
My difficulty with this sharpener is it isn't quite slim enough to be really
portable, but not quite thick enough to collect a lot of shavings. They made a
strange compromise with the size.
Also, fine wood shavings and graphite bits leak out of the pencil sharpener
unless you're careful to rotate the top back to the closed position after use.
The top is a little too snug to convenient slide back closed, but any looser and
it would probably pop off.
If they had simply made the metal sharpener core flush to the outer edge little
would leak out and you wouldn't need to close it.
I prefer the long-point sharpener, or a cheap barrel-shaped sharpener with the
hole in the top, instead.