Japanese 1000x Water Stone
They are aluminum oxide abrasive in a resin bond. In our testing, they were effective in O1 steel but noticeably slower in tough alloys such as A2. The particles fracture and dull after a short period, performing like progressively finer grits, which allows you to move from a medium grit straight to a finishing stone. They are economically priced, require only a quick soaking before use, and are a good choice for honing softer tool steels or when cost is a concern.
This 1000x stone is 7" × 2 1/2" × 5/8" mounted to an 8 3/8" × 2 3/4" plastic base that has two non-slip grip pads on the bottom.