This is a GREAT device to make it easy and less of a hassle to set up your sharpening job. Instead of the bucket and 2x4 piece of wood setup that a lot of people use (with damp rags to steady everything), just set your stone (with or without stone base/holder) on the bridge and adjust the width so it sets snugly across your sink, plug your sink and fill partially with clean cool water and you're ready to go. Makes keeping the stone clean and wet easy by simply reaching down and splashing some water up on the stone as you work.
It is very well-made, of heavy-duty aluminum -- strong and stable. Fits stones between 200mm to 250mm (8" to 9.8") long (and just about any height or width). Fits sinks from 400mm to 550mm (15.75" to 21.65") wide (front to back). This can be used alone, or with a stone holder/base for the ultimate in convenience and stability. Made in Japan.