This advanced engineering design reproduces high resolution sound from your regular headphone when using iPod, iPhone or iPad. The power supply and battery-less design make this amplifier ultra-compact and the aluminum bezel control panel gives you quick access to music selection and volume control. Deep Bass is designed to truly present the original sounds produced by professional musicians, artists, and producers in the way they want to be presented. Why spending hundreds of dollars for a professional headphone when you can get the same effect using your standard headphone powered by this compact headphone amplifier?