Brand name: ESTG System: IOS, Android operating system Function: Passometer, Sleep Tracker, Week, Heart Rate Tracker, Answer Call, Make Call, Remote Control, Push Message, Alarm Clock, Fitness Tracker, Message Reminder, Call Reminder RAM: <128 MB SIM card available: No Type: on the wrist Network Mode: None GPS: No Multiple spheres: Yes Battery capacity: 220-300mah Mechanism: Yes Origin: Mainland China Compatibility: All Compatible Compatibility:  All Compatible ROM:  <128 MB Rear camera:  none Waterproof grade:  life waterproof CPU Model:  JLAC6954 Band material:  silica gel Removable Battery:  No Screen shape:  Round Resolution:  360*360 CPU Manufacturer:  Mediatek Screen material:  TFT Screen size:  1.32 inches Certification:  CE Age group of application:  Adult Style:  SPORT Movement type:  Electronic App download available:  Yes Case material:  Alloy Removable Band:  Yes