iFi Nano iCAN Portable Headphone Amp for iPod/iPhone/Android/Mac/PC Small, compact and convenient with up to 70 hours of playback via the rechargeable lithium-ion battery 3.5 mm jack for easy plug-n-play to your mobile, smart device, desktop, laptop or other media player 3D HolographicSound system offers "out of the head" high performance stereo sound to make this the perfect audiophile accessory XBass delivers amazing bass boost and user-selectable gain and volume control work with any headphone sensitivity DirectDrive technology and quality, low noise circuit design reduce distortion and enhance dynamics