<p>Charge before using!&nbsp; (The connecting process has been introduced in the manual with details, please read it before using the earphones)</p> <p>Battery lasts 50 mins each time.</p> <p>If no sound in one earphone, sync the earphones as described in the manual:</p> <p>1. Set up two earphones in the status of red and blue lights interval flashing both&nbsp;, and then click twice in one earphone.&nbsp;</p> <p>2. If