This portable music system is completely programmable or you can attach an IPod or USB stick to it. It has a power supply or runs on batteries. You can hook it externally to a system for play through a sound system or a jack for headphones. Its a great little machine for a teen's room or someone taking dance. Multiple setting for dance arrangements while practicing. Sturdy hard shell and one end is flat to stand up on or the other end has loops for hanging. Originally cost $299 so I am firm on the price. Cross-posted.