This 4G Kids Smart watch tracker is designed to ensure your kids are always in contact. With a 4G nano SIM card input, you can call your kids wherever and whenever you need. Also with a built in Android system, you can communicate with your kids via video or voice call. There is also sleep monitoring and movement steps. With GPS, WIFI and LBS you can also know exactly where they are. And finally IPX66 waterproof will ensure the watch can withstand sweat, water and rain.