4-channel mono micro mixer, designed to be compact and easy to use. The MM-290 is a simple, small mixer with 4 mono input channels and 1 mono output channel. With simple controls consisting only of volume knobs for each channel and a master volume that also serves as the power switch, it's useful for when you want to easily add more channels or simply keep your signal lines streamlined. Its compact body makes it easy to handle, and it can be powered by a 9V battery, commonly used in guitar effects pedals, allowing for use in locations where it's difficult to secure a power supply, such as outdoors. 【Specifications】 Input: 4ch (1/4 inch mono phone jacks) Output: 1ch (1/4 inch mono phone jack) Weight: 420g