Bluetooth Headphones GJT&reg;BTH-700 Sweatproof Bluetooth V4.0 Wireless Headset Earphones In-Ear Earbuds with Microphone&Stereo for Sports (BLUE) DURABLE AND STYLISH: sports headphones for Cycling, Running, Climbing without annoying cables,about 3 hours playing time, 1 hours charging time, 80 hours standby with a single charge. The earbuds may fall out : Please use different size of earbuds which is included in package, to fit the shape of ears. PERFECT HI-FI STEREO SOUND: GJT BTH-700 built-in HD Mic and Bluetooth V4.0 version,ensure Hi-Fi stereo music sound quality and strong signal. Headphone will not charge or charge correctly: Please use the micro USB cable connect with computer to charge instead of using adapter. Because use adapter to charge ,the output may be higher than the input of headphone, it may has caused the headphone charge incorrectly or not been charged. MUSIC & CALLS CONTROLS: GJT BTH-700 allows automatic switching between music and calls. You can control all functions of music and calls easily via the button of Bluetooth headset. Built-in microphone enables taking hands-free calls while listening to radio.Can connect with two devices. INTELLIGENT NOISE REDUCTION : Use CVC noise cancellation technology reduces outside noises, you can enjoy crystal music and clearly microphone sound. If the headphones does not work properly or any other questions ,please let customer contact us in any time. We will provide fast service to them. COMFORTABLE TO WEAR: Ergonomic in-ear headsets design to specifically fit the contours of your ears,with medical grade silicone ear gels and stabilizers, providing you the most comfortable wearing earbuds full day.