Key benefits Simplified source control with a single knob. Doubleclick to switch audio sources in a circular sequence, reducing button clutter and keeping your setup tidy. Flexible source options. Supports Bluetooth, TF card, and AUX, allowing seamless playback from multiple devices. Easy power management. Longpress the knob to turn the device on or off, providing quick and reliable control. Clear operating information. Function name indicates Operation Mode and Status for simple, ataglance understanding. Core features Audio sources: Bluetooth / TF card / AUX Source switching: Doubleclick the knob to switch circularly Power control: Hold the knob to turn on/off Indication: Function name Operation Mode and Status Use scenarios Incar audio system: switch between Bluetooth streaming, TF card music, or an auxiliary device without fumbling with multiple inputs. Desktop or home stereo: easily select between a phone's Bluetooth, a TF card playlist, or an AUXconnected player for versatile listening. Portable speaker setup: convenient source changes during outdoor events or gatherings, with minimal setup and intuitive knob control.