Model: I2 CPU: MTK6580 Sensor: Gravity Sensor, Heart Rate Sensor OS: Android 5.1 Smartphone OS Compatibility: Bluetooth 4.0, Android 4.3 or above, i OS 7.1 or above SIM type: 1 SIM Card 1 Standby (Micro SIM card) 3G Network Frequency: WCDMA 850/2100 M Hz 2G Network Frequency: GSM 850 / 900 / 1800 / 1900 MHz Bluetooth: 4.0 RAM: 512MB ROM: 4GB Screen