NOTE:<br />  1)Please insert the TF card & SIM card together in the watch so that all function works.<br />  2)Please take out the battery and insert again when it could not be powered on.<br />  3)In order to extend the life span of the watch and battery｣ｬplease don't charge more 3 hours.<br />  4)Please use the watch to connect mobile phone's bluetooth if the phone could not search it.<br />  5)All functions work with Andrioid phones only｣ｬ bluetooth available for ios phones.<br />  6) The watch provides with the daily waterproof｣ｬ it can't wear to swim｣ｬ take a bath or put in into water.<br />   Q18 smart watch support max 8 GB external memory card.<br />   Q18 smart watch supports single micro sim card｣ｬ it supports 2G network only(850/900/1800/1900MHZ)｣ｬ so only the sim card which supporting 2G network can work on Q18 smart watch. you could make a call or send messages directly through the watch without connecting the watch to your mobile phone as long as a sim card which supporting 2G network was inserted into the watch.The link speed to internet is very slow due to the watch supports 2G network only｣ｬyou almost can't open any website through the watch｣ｬ so it is not a good choice if you want to use the watch to surfer internet.<br />       Q18 smart watch is completely compatible with android system(Android 4.2.2 and later version)｣ｬ all apps which were installed in Q18 smart watch can work on android system｣ｬ but some functions need to work with the sim card and some f