I purchased this at a store and used it for about a month. I am selling it now because I don't have much use for it. ■Product Description ・The firm cushion provided comfortable seating without any pain. ・It is in relatively clean condition with no scratches or stains. ■Size Outer diameter: 40cm Inner diameter: 12cm *Please note that there may be slight variations due to amateur measurements. Please consider purchasing if you understand that this is a used item. Thank you for your consideration.