Connect Your Portable DAC to Your Smartphone Along with a Separate Power Bank with iBasso's CB19 USB-C Cable and Y Adapter USB-C to USB-C connection with USB-A for power Get clean quality power with minimal interference while preserving your phone's battery Premium grade high-purity Silver-plated Copper About 3.9" long (100mm) Clean Power. Minimal Interference Smartphones typically have a restricted output current for OTG devices. Furthermore, smartphones yield a lot of internal interference, so powering from them isn’t the most ideal. With the CB19, dongles can power from a clean source, such as a power bank, instead of your smartphone. Your DAC dongle gets quality power with minimal interference with the CB19 while simultaneously preserving the battery on your smartphone, achieving optimal performance from both your phone and the dongle.