The Cartridge is a no-gimmicks iPhone 4S/4 case that is more durable than it appears. You really can't judge a book by its cover when it features a reinforced rubber perimeter that protects from drops that would normally cause damage to any other case or the phone itself. The hard shell back panel prevents scratches and provides critical back protection while adding grip with its raised and textured design.
iPhone 4 for ATT (GSM)
iPhone 4 for Verizon (CDMA)