Apogee Quartet USB Audio Interface AD/DA conversion for recording up to 192kHz / 24-bit. USB 2.0 High Speed connection to Mac or PC. Direct digital connection with iOS devices (iPhone, iPad and iPod touch. 30-pin/ Lightning cable sold separately). Monitor control for up to 3 sets of speakers or 5.1 surround. Software control of hardware parameters including input selection and low latency monitoring.