Padgene NFC Bluetooth Smart Watch with HD Screen for Samsung S3 / S4 / S5 / Note 4, HTC, LG, iPhone (Partial Functions) and Other Android Smartphones, Black You can insert a micro-sim card to the slot to make and answer phone calls, good for T-Mobile, Straight Talk, Simple Mobile, or any other carrier that accepts a 2G GSM Sim Card. Will NOT work with 3G only providers like ATT, Will NOT work with any CDMA Carriers (Verizon, Sprint, Boost, PagePlus), or you can make phone calls by connecting it to your Android/IOS smartphone via Bluetooth. Automatically track your steps, distance, calories burned,monitor your sleeping at night, sedentary reminding,receive notifications from your smartphone, calculator, calendar, alarm clock, recording etc. Enjoy your music by connecting watch to your smartphone or inserting a micro-SD card and download your musics, you can even connect your Bluetooth earphone to the watch to listen to the music. All Android and iOS Mobile Phone & Android Tablet PC. Android Mobile Phone: Samsung, HTC, Sony, LG, HUAWEI, ZTE, OPPO, XIAOMI, and so on. iOS Mobile Phone: iPhone 7/7 plus,iPhone 6, iPhone 6 plus, iPhone 5, iPhone 5s , iPhone 4, iPhone 4s (This APP can' t be installed by iOS, Apple system can' t sync SMS and Bluetooth push information, but other functions can be used by iPhone) Find the QR code in your watch, scan the code with your smartphone or you can handle this according to your manual, you can also turn to Padcod for assistance.