The boxes are constructed of white corrugated paper. Holds about 450 standard 20pt trading cards. Holds about 720 collectible gaming cards. Exterior Dimensions (WxHxD): 9-7/8 x 3-1/4 x 4-1/4. Interior Dimensions (WxHxD): 9 x 3 x 3-7/8 Horizontal Trading Card Dividers - These polyethylene trading card dividers fit perfectly in single row boxes, and have a fold-over. write-on tab to keep your cards sorted and organized