Model: W9-SN07 CPU: MTK6261 Sensor: Gravity Sensor, Heart Rate Sensor, Triaxial Accelerometer Smartphone OS Compatibility: Android 4.3 or above SIM type: 1 SIM Card 1 Standby (Micro SIM card) 2G Network Frequency: GSM 850 / 900 / 1800 / 1900 MHz Bluetooth: 3.0 RAM: 128MB ROM: 32MB Screen