Teijin high-rebound cushion, circular with a 40cm diameter. It's firm and won't sink in. The cover has a zipper and can be removed and washed. I purchased it from the Teijin official website for 3500 yen, but I no longer have the opportunity to use it, so I'm selling it. Thank you. Size: 40cm (length) x 40cm (width), 15cm (thickness) Color: Beige Stylish floor cushion, zabuton, round, firm, hard, thick, resistant to sagging, round cushion, thick, Nordic, square, round, pipe, cushion cover, floor, chair, seat cushion, durable, doesn't cause fatigue, breathable, washable, Teijin, TEIJIN, no bottoming out, thick, cover, washable, circular, round, extra thick