USB Sport MP3 Player w/microSDHC Slot (Black) - Behind-the-Head Stereo Headphones w/Built-in MP3 to Work Out Tangle Free USB 2.0 Sport MP3 Player General Features: Color: Black Supports up to 4 GB storage Comfortable behind-the-head stereo headphones with built-in controls and LED indicator Built-in Lithium-polymer battery Supports MP3, WAV and WMA formats USB 2.0 high-speed interface Specifications: Lithium-Ion Battery Audio Formats: MP3/WMA/WAV S/N Ratio: 86dB Output Frequency: 20Hz - 20 kHz