Features:1.Built-in TF/ micro SD card slot support up to 8GB TF/ micro SD card( card NOT included).2.Just save your loved songs in TF/ micro SD card and then play them with this sport player.3.Doubles as a TF/ micro SD card reader if connect it to computer.4.Supports MP3 WMA music format.5.Built-in rechargeable li-on battery and charge by USB cable.6.Easy to use, "On/ off" toggle and 3 Key-press: Play/ Pause, Volume / -(long press),Previous/ Next (short press).7.Comfortable and secure for most users: bicyclist, runners, joggers, walkers, etc.8.Wrap around wire free headphones, designed to stay on your head.9.Great quality, super stereo sound lets you enjoy your sports and music at the same time!Specifications:1,Color:Green2.Audio format: WMA, MP33.S/N ratio: ? 86db4.Output frequency: 20Hz—20KHz5.Port: Mini USB6.Battery: DC 3.7V Li-po battery7.Charge time: 2-3 hours8.Playtime: Approx.3 hours9.Supporting system: Windows 98/ ME/ 2000/ XP/ Vista/ 7, iOS10.Working temperature: 0 Celsius degree-45 Celsius degree11.Headset size: Approx. 14 * 13cm/ 5.5 * 5.1in