Lenovo Vibe Z K910 Dual Sim Quad Core 2.2Ghz Smartphone Unlocked Cell Phone Lenovo Vibe Z K910 Dual Sim Quad Core 2.2Ghz Smartphone Unlocked Cell Phone CPU & GPU: Qualcomm Snapdragon 800 Quad-core 2.2 GHz Krait 400 , Adreno330 Memory: RAM 2GB , ROM 16GB Screen: 5.5 inches (~401 ppi pixel density) 1080 x 1920 pixels, 13 MP/ Auto Focus , LED flash Other: WCDMA /GSM , Android OS, v4.2.2 (Jelly Bean) , battery 3050 mAh 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.