This is a tea bowl, a Tatara-yaki piece from the Kaneko Kiln, made by Ninsaku Kaneko, purchased by my father in 1972 (Showa 47). It has been stored away and is unused. I don't know the details, so please judge from the photos. I think it's just the right size for a matcha bowl. Diameter: 11.7 cm Height: 7.5 cm Please note that these are approximate measurements.