Micro Mixer Number of Channels: 4 Item Weight: 0.41 kilograms Power Source: Battery Powered, Corded Electric DC9V Output Connector Type: 1/4 inch Mono Phone Audio Input: 1/4 inch Mono Phone Input: 4Ch (1/4 inch Mono Phone) Output: 1Ch (1/4 inch Mono Phone) Dimensions: 150(W) x 85(D) x 45(H) mm Weight: 0.41kg Purchased about 10 years ago. It shows signs of use, but works without any problems. This is a simple mixer that mixes 4 channels of mono input and outputs them from a single mono output. It has various uses, such as when you need more inputs or when you want to combine the audio from multiple karaoke microphones. It can be powered by a 9V battery, making it suitable for use in street performances. It can also be powered by a DC9V (center negative/200mA/terminal diameter 5.5/2.1mm) adapter (recommended model number: KACA-1).