LIBERTY WITH MP3 PLAYER INSTALLED AND 2 WIRELESS RECEIVERS. Perfect for outdoor and indoor events. Covers 2,000 people. AC powered. Two wireless receivers built in and built in MP3 player. 10? neodymium driver provides increased dynamic range and it?s lightweight. USB charging port for iPod® or other music playing devices. Great for assemblies, graduations, presentations and any other activity indoor or out.