I purchased this item as new on Mercari previously. When I bought it, it came in a box that said 27 centimeters. There was a marking on the side, likely a product number, written in marker from the time of purchase. There are no issues with its use. I used it a few times at home, but haven't used it since, so I'm putting it up for sale. I think it's effective for balance training, core training, and improving posture!