Made from lycra cloths, the card holder is high quality and quite stretchy, allowing you to store up some cards or cash, ID card, credit cards, keys, pencil, ear buds. It can hold about 8 cards at the same time without losing its shape. 3M sticker makes the card holder strong enough on any smooth surface, such as glasses, back of smooth cell phone, smooth leather phone case, removable clean without glue trails and reusable. With the advantages of light weight and ultra slim, the wallet holds up some cards and some cash so that you don't need to carry a big bulky wallet in pocket and keep them safe. The card holder can not only be attached to back of phone, but also can used as storing up pencils, rulers, pens in office for convenience and beauty. The color can be customized.