If the device has only one microphone or musical instrument interface, this unit can be used to increase the number of expansion interfaces, achieving the goal of multi-channel input. It has five inputs and one output. The five-channel input is mixed into a single-channel output, and the volume of each channel can be adjusted independently. It is equipped with a delay reverb function, and the reverb volume of each channel can be adjusted independently. Input and output: 6.35mm 1/4Inch mono interface. Charging: TYPE C interface, DC5V, and it can be charged using a mobile phone charger. Battery: 18650 (2000mAh), removable. Gain: 0dB/10dB, switched by a button switch. Indicator light status: Flashing continuously 4 times indicates a 4-grid battery level, 3 times indicates a 3-grid battery level, and so on. It stays on when fully charged. Colour:Black Material:Metal Package Contents: 1 * microphone extender 1 * USB charging cable 1 * 6.5mm audio cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.