Bluetooth speaker:Built-in bluetooth speaker connected with your cell phone,you can enjoy your music while biking, hiking in full relax music time! Lost reminder device built-in Swissdigital LOGO, connected by bluetooth through download "Dtracing". Alert for Lost-reminder: Both the device and phone alert when distance between them is beyond 9-15 meters(Actual distance varies in different situations). Second alert will come if they continues to be beyond safety distance for 18 seconds; Bluetooth is off, and no connection will cause alert, it will automatically connect the device when it search out the device. Searching for items: Press the button Alert on Device List to switch on/off alert of the device; Double click the device button to activate the alert of phone. Photograph: Press Photograph button to open camera in APP. Press camera setting on the right bottom to set burst shooting and interval time. Location: when not in state of Photograph , click the device button to locate current position. Enter Location to check location list and lost history. Recording function: Enter Setting , open Double Click Setting and select Recording . Double Click the button to start recording, then double click to end up recording. Setting: Enter setting, all phone alerts for the device can be deactivated after switch on Do Not Disturb , APP Password can be set up; change different maps through Map Switch ; enter Double Click Setting and check recording history, etc.