This is the "magnetic board (magnet board/practice board)" from the "arithmetic set" by Kobun. It was used in elementary school. Although there is warping and dirt on the back, I believe it can still fulfill its role as a learning tool using the arithmetic set. Therefore, I will offer it at the lowest price to those considering a replacement for their children. Please understand that this is a used item, inspected by a non-professional, and stored at home. Thank you for your purchase. m(_ _)m