It's so tiny!!! It sharpens 2mm leads for Lead holders, like TK 9400/TK4600, Staedtler 780, etc. Luckily, it has a little hole so you can attach it with a string somewhere, so you don't lose it! It works much better than the sharpeners that sometimes come with pencils of this type, and together with the 18 66 00, they are the best portable ones in their category!
CAUTION, M+R and KUM have copied the same one, but I would recommend them in the order I wrote them. The same goes for the 18 66 00, only this one has been copied only by KUM. They are the only sharpeners that I prefer the Faber Castell version, not KUM. KUM, especially this tiny one here, has the same quality, appearance, and tip as Faber Castell. KUM produces a slightly sharper tip, but it breaks immediately with the first use, and at the same time, the plastic and overall quality do not resemble Faber Castell at all (These apply ONLY to these sharpeners because in all others, KUM is THE BEST in the world and Faber Castell is mediocre in quality. See KUM Automatic Longpoint, etc.)