Performs reference quality digital-to-analog audio conversion for music played via compatible Android smartphones Compatible with Samsung Galaxy S3/S4/Note2, HTC One, and other Android devices with USB OTG and USB digital audio output capabilities Also works with laptop and desktop computers at up to 24-Bit and 96kHz bitrate high definition audio High-end op-amp audio output circuitry with ultra low distortion and noise. Large 3500mAh battery for up to 25 hours of use as an amp-only, or up to 12 hours as DAC+amp. Charges in 4 hours with optional 2A USB adapter.