card enclosure is a container for smart cards , credit cards , debit cards , telephone cards , visiting cards , business cards and other cards of similar size. ID-1 format of the ISO / IEC 7810 standard. The size of the physical dimensions is 85.60 × 53.98 mm. The enclosures can be made of metal, leather, or plastic and come in various colors and designs. Sometimes having a laser engraved design for aesthetic purposes.

There are shaped CDs that are also sized.

If made of aluminum , it may provide RFID shielding for proximity cards .