Used bowls, set of 15. I believe they are made of plastic (synthetic resin?). Diameter: Approximately 11.5 cm Height: Approximately 6.5 cm These are used items. Some have sticker residue on the outer bottom (photo 4), and there are marks where stickers were removed (photo 5). There are fine scratches on the inside (photos 6, 7, 8). They have a Showa retro feel.