This unit doesn't come with an external power supply. However, it can be powered by a 9V battery (battery not included).

Using this Behringer Powerplay P1 Personal In - Ear Monitor Amplifier is easy. First, since it doesn't have an external power supply, you need to insert a 9V battery into it. Just make sure the battery is properly placed according to the polarity markings. When using, connect your in - ear monitors to the amplifier. This will give you a great audio experience. As for maintenance, keep it in a dry place and avoid dropping it. Also, when not in use for a long time, take out the battery to prevent leakage and damage to the unit.