This is a seiza (formal sitting) chair. It's used by people with knee pain when sitting in seiza. It also helps prevent your legs from going numb when getting up from seiza. When in use, it's 8 cm (length) x 18 cm (width) x 10 cm (height). It's portable. I've used it quite a bit. When stored, it's 8 cm (length) x 15 cm (width) x 2.8 cm (height). I found it while decluttering my parents' house. It has been stored at home for a long time. The market price isn't very clear, so I think I can offer a discount. Please leave a comment. Thank you for looking.