This is a knife sharpener designed for whetstones measuring 180 x 60 x 30mm (L x W x H). It also includes an adapter plate for a length of 150 mm. There are different angle rails included, 15°, 17.5°, 20° and 22.5°, which should cover most household and pocket knives. Based on request, a smaller version is also available for a whetstone of 150x50x25mm.