Note:Learn more about the M4 firmware upgrade by clickinghere. Features:- >Flagship-Grade Portable Bluetooth USB DAC/AMP. >Stable Bluetooth Connectivity With Latest Qualcomm QCC5125 Chipset. >3.5mm+4.4mm+2.5mm Headphone Sockets. >Independent HiFi Architecture With ES9038Q2M DAC Chipset. ...