The DAP PDI-200 is a two-channel passive direct injection box. It converts a HI-Z signal into a LO-Z signal. You do not need a battery or phantom power for this direct box. It is suitable for a wide array of applications, great for keyboard signals, acoustic & electric guitar signals and any other instrument signals that need to be plugged into a snake on stage. In addition, it has a 0/20/40 dB attenuation switch.