4.0-inch Retina display A7 chip with M7 motion coprocessor Touch ID fingerprint sensor 8MP iSight camera with True Tone flash and 1080p HD video recording Unlocked cell phones are compatible with GSM carriers like AT&T and T-Mobile as well as with GSM SIM cards (e.g. H20 and select prepaid carriers). Unlocked cell phones will not work with CDMA Carriers like Sprint, Verizon, Boost or Virgin.