The website for the KUM Special Diameter pencil sharpener seems reserved in describing the sharpener’s purpose:
8 + 10” Double Pencil Sharpener, for some special-diameter triangular pencils, with 8mm and 10mm holes, container has pencil hole cover, assorted red and black.
The idea of a specialty sharpener just for large triangular pencils is appealing, but it is hard to imagine the engineering behind such a sharpener. Note the octagonal pencils in the graphic:
The sharpener appears to be the usual fare:
And the sharpening result (not bad, in fairness) doesn’t convince me that this product is a specialty item: