From MXR:

The Micro Amp+ upgrades a classic boost circuit with EQ controls, low-noise op-amps, and true bypass switching to take this powerful boost box to the next level.

This pedal can be powered by a 9-volt battery, a Dunlop ECB003 9-volt adapter, or the DC Brick, Iso-Brick, and Mini Iso-Brick power supplies (not included).

Brand new.