This is a great unit to power 5-15 feet of el wire at high brightness levels. This power pack runs from 4 AAA batteries and offers both constant mode and a variable strobe control. Also it has a port for an a/c adapter (sold seperately) if you should choose to run it directly from a wall socket. This is a small encased unit with a belt clip. It is roughly 2" x 2" x 1".