Bubblepack RFID Card Compartment for iPhone 4/4S - Blue Protects the back of your iPhone from damage, dents, and minor scratches. Has a space in the back cover for RFID cards such as credit cards and subway passes for quick use. Innovative ultra slim fit design for iphone 4s & 4 High quality PVC for ultimate protection and virtually unnoticeable weigh increase Compatible with Apple iPhone 4 / 4S