V-MODA VAMP Verza Universal Headphone Amplifier, DAC, Battery Pack for Android, Apple and Computers (Shadow Black/Red) World's first docking headphone amplifier (150Mw x 2) for Android, Apple and Windows devices Two dedicated digital to analog convertor (DAC) chips uses mobile device's digital output for pure analog performance docking mechanism to transform your smartphone into a mobile hi-fi system 2200 mAh battery for charging of USB/iOS devices or 7 hours of audio play time Made in Japan - designed in Italy