Sony Xperia Tipo ST21i Unlocked GSM 3G Android 4.0 Touchscreen Phone - Black 2G: GSM 850 / 900 / 1800 / 1900, 3G: HSDPA 900 / 2100 3.2-inch Multi-Touchscreen w/ Scratch-Resistant Glass Android v4.0.4 (Ice Cream Sandwich), 800 MHz Cortex-A5 Processor, Chipset: Qualcomm MSM7225AA Snapdragon, Adreno 200 Graphics 3.2 Megapixel Camera (2048 x 1536 pixels) + Video Internal Memory: 2.9GB (2.5GB user available), 512 MB RAM + microSD Slot Expandable up to 32GB 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.