Here in Europe these are sold under the name Vulkanus sharpener, but are much more expensive.
There are two types: one with stainless housing and one with glass filled nylon housing.
While they do work better than those cheap pull-through sharpeners (the resulting edge looks cleaner & lasts longer), they also remove quite a lot of metal from a knife.
I would not want to use the better quality kitchen knives on them, but in situations where there are lots of cheap kitchen knives that need to be sharpened often and no one around who knows how to sharpen properly, a Vulkanus could be an option.
Think old folks homes, fishing wharfs, etc.