The DI 200A is a 2-channel active direct box (Direct Injection box in English), is an audio device used primarily in sound reinforcement and recording to adapt the signal from an instrument (such as a guitar, bass or keyboard) to make it compatible with the inputs of a mixing console or recording system.
It will convert your unbalanced (non-balanced), high-impedance signal (like that of an electric guitar) into a balanced, low-impedance signal. It will allow you to send the signal over long distances without loss of quality or interference. It protects the console and reduces noise like buzz and hum due to ground loops. The DI 200A contains an internal electronic amplifier (powered by a battery, an external power supply or the 48V phantom power provided by a console).