Block Rocker Speaker System - an all-in-one sound system for your iPod microphone or other audio sources. You can rock out with BLOCK ROCKER for more than 12 hours on its internal rechargeable battery or connect to an electrical power outlet. The large speaker and built-in amplifier make this a great speaker for announcements or music to carry throughout small parties. Connect a microphone (included)  CD/Mp3 player or iPod to BLOCK ROCKER  and you’re ready get the party going anywhere.