Concerning this item Strong JBL Pro Audio: Even at maximum volume, two 6.5" woofers provide clear, accurate, deep bass, and a pair of 25mm dome tweeters create incredibly clear highs. It was loud enough to fill a tennis court with music. Futuristic lightshow: Combine all that sound with an exciting light show that is timed to your beat and includes strobe light effects, cool light trails, and starry lights. Up to eighteen hours of play: Enjoy up to 18 hours of partying on a single charge from sunset to sunrise. Insufficient? After changing the replaceable battery*, continue dancing. You can play for an additional two hours with a 10-minute fast charge. Separately available, replaceable battery Wide, robust wheels and a telescopic handle: Roll.