High-quality Bluetooth DAC. The AK XB10 uses aptX HD technology, the latest Bluetooth codec from Qualcomm. 24-bit HD audio that was simply not possible with previous Bluetooth technologies can now be fully enjoyed with aptX HD. Along with DAC, amp, and essential components of fine audio, the AK XB10 delivers a distinctive difference in sound from conventional Bluetooth products. FeaturesCapable of transmitting up to 24-bit/48 kHz audio that is faithful to the original audio file.Equipped with a Hi-Fi DAC capable of reproducing high-quality sound up to 24-bit/192 kHzEquipped with both 3.5mm unbalanced & 2.5mm balanced audio outputsCompatible with all iOS, Android, and many other Bluetooth devicesSupports voice calls and features a built-in microphone: receive calls when using earphones without a microphoneInspired by Astell&Kern's principal design motif of light and shadow.