Made Of Aluminum With Elastic Strap. Holds 6-8 Credit Cards Or 10-15 Business Cards. Place Your Credit Cards In Holder To Prevent Cyber Hackers From Stealing Your Identity. Prevents Data Transfer Between The Wallet And Reader. Works With Any Contactless Chip Card. Cards That Are Swiped Do Not Send RFID Signals And Will Not Be Protected By An RFID Blocker.