The size is quite large at 7.5 x 7.5 x 5.0. Please check the stamp face in the photos. There are also photos taken with a flash to make the scratches more visible. These scratches were already present from the time of purchase. Please be careful not to make a mistake if you are a beginner in seal engraving. This is not in mm. It also has weight. I purchased this at Shoyu for an exhibition, but it has remained unused, so I am offering it for sale this time. I do not remember the specific type of stone, so I cannot specify it. Please judge by the photos. It is definitely not Seiden Seihakusho stone. When shipping, I will carefully wrap it in packing material to prevent damage.