Set of three of the same size. The color of the plastic fixing part on the back of one is slightly different. There are traces of tape where a photo was attached to the back of the mat. It is not visible from the front. The transparent part is glass. It is sturdy and has weight. The mat can be removed, so how about for photos or art? Please see the images for the outer and inner diameters. There are memos such as the date of photography on the outer box. I will wrap the outer box in bubble wrap and ship it. I don't see any major damage, but there may be minor scratches or scuffs. Please understand that this is a used item before purchasing.