MATERIAL: lycra, quite stretchy, allows you to store up to 8 cards & cash, earbuds ect. If 8 or more cards have been inserted and then taken out, pls allow at least one night for the loose card holder to recover close to its original size.Using 3M adhesive, COCOFU card holder securely attaches to the back of your device, no extra super glue needed. It removes cleanly too! No residue left. SLIM COMFORT, STRONG ELASTICITY - The COCOFU wallet attachment features durable stick work that ensures the pocket never loses elasticity or stays open when not in use. In fact, it's so thin and compact it won't add bulk or make your phone harder to carry even when in a front pocket, purse or handbags. DOUBLE SECURE, DISCREET DESIGN - These adhesive pockets can also be used as a secret pocket in a personal locker, glove box organizer for parking cards or cash, or even as a hidden compartment for your gym bag.Double Secure with Lid Cover than Regular Attach on Case.