This is a fine grained natural whetstone supplied by Schroeckenfux. It is 23 cm long and has a grit of about 600. It is named after the village where it is quarried. Just fits in the metal holders. An unusual whetstone made of a schistose sandstone. The extremely thin sedimentary layers in the stone, naturally sandwiched together, give it an unusual feel when honing, like using two different gritted stones at the same time. The soft layer creates quite a slurry, when used.