The Calyx Audio PaT headphone amp may be small but it packs a big sonic punch. Use it to upgrade the sound quality of your Android and iOS devices when playing iTunes, Spotify, Pandora or any other music app. The specially designed headphone amplifier provides superior sound and build quality over the cheap amplifiers in the device. Milled from a billet of aluminum the little PaT amp contains an asynchronous 16 bit, 48kHz USB digital to analog converter for superb sound quality. Buttons for play/Pause, volume +-, track skip forward and back (iOS only). Two cables are included, a Micro USB OTG and a micro USB to USB. Apple Devices without a USB port will need Apple's Lightning to USB Camera Adapter which is NOT included and sold separately. About Calyx Audio Digital & Analog (D&A), the parent company of Calyx Audio, designs and manufactures class D output devices for industry brands such as Samsung. Passionate music lover, CEO, and designer Seungmok Yi, started Calyx Audio in 2008 with the goal of bringing music's essence to people through technology.