Docooler Sport MP3 WMA Music Player TF/ Micro SD Card Slot Wireless Headset Headphone Earphone (Black) Built-in TF/ micro SD card slot support up to 8GB TF/ micro SD card( card NOT included). Just save your loved songs in TF/ micro SD card and then play them with this sport player. Built-in rechargeable li-on battery and charge by USB cable. Comfortable and secure for most users: bicyclist, runners, joggers, walkers, etc. Wrap around wire free headphones, designed to stay on your head.