PRO-Binders are ideal for storing and sorting valuable trading cards. Textured black backing material provides easy, low-friction way to insert cards while giving cards a classic framed look. Side loading pocket prevent cards from easily falling out. Elastic strap holds the binder shut when not in use. All materials made from archival-safe, acid-free non-PVC material. Holds up to standard 2-1/2" x 3-1/2" sized cards in standard Ultra PRO Deck Protector sleeves.