SIM Card Slot : NANO SIM Card Voice assistant built-in : YES Bluetooth-compatible Version : 4.2 Wi-fi : YES Metrics measured : Heart Rate Monitor,Blood Oxygen Monitor Activity Tracked : Steps Tracker,Distance Tracker,Calorie Tracker,Activity Tracker Touch Screen : YES Category : Smart Watches Screen Material : LCD CPU Model : SL8541E Band Detachable : Yes APP Download Available : Yes Battery Detachable : No Resolution : 360*360 Display Size : 1.52 inch Movement Type : Electronic Style : Fashion Application Age Group : Adult Screen Shape : Round Case Material : Alloy Band Material : Silica gel Waterproof Grade : Life Waterproof SIM Card Available : Yes Mechanism : Yes Multiple Dials : Yes GPS : Yes Network Mode : 4G Battery Capacity : >450mAh Rear Camera : 2MP RAM : >2GB ROM : 128G System : Android OS Type : On Wrist Compatibility : All Compatible Language : English,Russian,Spanish,Polish,Portuguese,ITALIAN,French,German,Norwegian,Japanese,Ukrainian,Hebrew,Dutch,Arabic,Indonesian,Greek Function : Passometer,fitness tracker,Message Reminder,Call Reminder,Answer Call,Dial Call,Remote Control,Push Message,24 hour instruction,Chronograph,Alarm Clock,World Time,Power Reserve,week,Month,Heart Rate Tracker,Interactive Music,Calendar,Calculators Certification : CE,FCC,RoHS Model : K8 smart watch