HTC Butterfly X920D Unlocked GSM 4G LTE Android Smartphone w/ Beats Audio Sound, 8MP Camera, Quad-Core Processor- Black Display: 1080 x 1920 pixels, 5.0 inches (~441 ppi pixel density) - Corning Gorilla Glass 2 Internal Memory: 16 GB (11 GB user available), 2 GB RAM Camera: 8 MP, 3264x2448 pixels, autofocus, LED flash OS: Android OS, v4.1.1 (Jelly Bean), planned upgrade to v4.2 (Jelly Bean) CPU: Quad-core 1.5 GHz Krait - GPU: Adreno 320 Unlocked cell phones are compatible with GSM carriers like AT&T and T-Mobile as well as with GSM SIM cards (e.g. H20, Straight Talk, and select prepaid carriers). Unlocked cell phones will not work with CDMA Carriers like Sprint, Verizon, Boost or Virgin.