Natural whetstone, Aiwadani. The surface was prepared by myself from the raw stone. Since it's a DIY level by an amateur, please refrain from purchasing if you are looking for perfection. I think this is perfect for those who want to try natural whetstones but think the authentic ones are too expensive. There are layer cracks and chips, so areas other than the whetting surface are coated with cashew lacquer. The sharpening impression is a bit hard, with a bright, cloudy feel. It also has a sharpening feel similar to Nakayama's yellow plate. You can use it for both the cutting edge and the small edge. The shape is not good, but it's a good whetstone. Since it is a natural product, there may be streaks or dragging that I couldn't detect when I tested it. Please consider this as well before purchasing. Length: Max 147mm Width: Max 70mm Height: Max 21mm