1. If the device has only one microphone interface, eight microphones can be expanded and used simultaneously through this unit 2. The 6.5 dynamic microphone interface of the audio amplifier or outdoor speaker cannot use the electret pickup, which can be achieved through this unit. 3. Eight microphone inputs. The 3.5mm interface has a bias voltage and can be connected to electrets and common condenser microphones (48v, please connect to an external power supply). The volume of each channel can be independently controlled and can be completely turned off. After the mixed output, it can be connected to a desktop computer or sound card active speaker. and other audio equipment. 4. Power supply: DC5V, comes with a USB power supply cable, which can be powered by a computer USB interface or a mobile phone charging head. Colour:Black Material:Metal Package Contents: 1x Host 1x DC line 1x 3.5 audio line 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.