Trendy USB Ear loop Headphones Earphone FM Sport MP3 Music Player W/ TF SlotThis wireless earphone is speically designed for sporting.Insert your TF card，you can use it play musics included in your TF card.It also can be used to listen radio.It is light，easily to take during do sports.Looks fashion.If you forget your cardreader，it can be also used as a card reader by connecting it to a computer through USB cable. Audio Formats: Mp3. Five buttons:Power on/off，foward，backward，pause，and mode. Capacity: 128MB-32GB. S/Nratio: >=86dB. Build-in TF Card slot.(Supports 1-32GB TF card) Power by USB cable. Output frequency: 20hz-20khz. Built-in rechargeable li-on battery. Compatible system:Windows 98/2000/XP/Vista/7 Weight: About 40gFour colors for option:Black，Blue，Green，BluePackage includingSport MP3 x 1USB cable x 1