With box, authentic! Purchased at GALLERY 2 (The original purchase sticker is on the included box) 27.5 cm A popular size. I usually wear Nike sneakers in sizes 26.5 or 27, but for basketball shoes, I go up 0.5 to 1.0 size, and this was a perfect fit. Used in a gymnasium for about 1 hour, approximately 10 times, for shooting practice, etc. There are no particular stains. (Only the laces have a slight color transfer from the shoes) This is a personal inspection, so please understand if there are any minor imperfections. Please understand that returns and exchanges are not possible for used items!