1. App (Se Tracker) system required android (os 3.0 or above)、 ios phone (ios 6.0 or above)2. Saving telephone numbers in the Se Tracker App setting's telephone、 kids can answer and receive calls 、 but when saving in the contacts、 kids can only receive calls、 can't make calls!Introduction:This is theExcelvanKids Smart Watch q50 not only have the children's safe position function but also have the common smart bracelet's function、 such as sport monitoring、 sleeping monitoring and alarms. Of course、 the Safety is the first priority especially for the children. As a kids Safe smart watch、 it has GPS and LBS double location for accurate position. It is also a quad band GSM (850MHz、 900MHz、 1800MHz、 1900MHz) unlocked phone that can be used anywhere all over the world. Sticking in a 2G SIM card and you can call on your wrist.For better use、 we develop the unique APP: Se Trackerto take care of your kids. You can set SOS/Family number、 Contacts、 Telephone numbers in the APP、 which avoid the stranger calls to your child. Meanwhile、 the Geo fence、 Voice monitoring、 Message alert、 History route etc which let you know more better of your child.To live a happier and relax life、 buy it for your children or friends'、 relative's children. It's our pleasure to help you a safe and health life.