This Mini503 Wireless Stereo V2.1 Bluetooth Back-mounted Sporty Headphone is a must-have for your sport， such as jogging， skating， mountaineering， etc. Adopting imported and superb CSR Bluetooth smart chip， this headphone ensures stable Bluetooth receiving. Besides， wireless design is great to get rid of twined cable and and make you enjoy wireless experience. Three-dimensional buttons design for convenient and quick use. With making calls function， you just press the button if comes in call during listening music. It is applicable to desk computer， PC， tablet PC， mobile phone， etc. In addition， back-mounted design does not exert influence to sport， making calls. What are you hesitating for?                                    Features             Support V2.1 Bluetooth wireless play and transmission<br> 10m wireless transmission range<br> Support high-quality stereo play<br> 40mm neodymium speaker<br> Ultra long calling time and standby time<br> Suitable for all mobile phones with Bluetooth function and computers<br> Mini and compact design for convenient carry<br> Foldable steel is retractable and comfortable to wear <br> Soft and permeable earmuff <br>                                                            Specifications             Speaker Diameter     1.57" / 4cm    <br> Sensitivity     105dB S.P.L at 1KHz     <br> Frequency Response     20Hz-20，000Hz     <br> Rated Power     25mW    <br> Bluetooth Version     V2.1    <br> Transmission Power     Class 2     <br> Radio Frequency     2.4-2 .48GHz     <br> Transmission Distance     10 Meters     <br> Charging Time     3 Hours     <br> Talking Time     10 Hours    <br> Music Playing Time     Up to 7 Hours    <br> USB Cable Length     23.62" / 60cm    <br> Weight     1.48oz / 42g    <br> Color     Black    <br> Compatible with     Universal    <br> Dimensions     (13.38 x 1.77)" / (34 x 4.5)cm (L x Dia.)     <br>                                                             Package Includes            1 x Bluetooth Sports Headset<br>1 x USB Cable<br>1 x User Manual<br>