This is a modified Cambridge Soundworks Ensemble II sub woofer that was about to be thrown away due to age at our town dump. I salvaged the sub woofer and replaced the dry-rotted speakers with 2 Pyle 6.5in sub woofers, added 2 Alpine co-axial speakers to the side, and a CNC milled shelf with a Pyle Bluetooth enabled amplifier, panel for interior lights, and a pocket for your phone. The sub woofer enclosure has also been modified by being upside down, the bottom (now top) panel being replaced with 1/2in thick lexan, and a handle on top. Battery life is 12+ hours and weighs less than a fully-stuffed backpack during finals week. Since this speaker was recycled from a sub woofer enclosure, its bass response is the on of the best of any speaker I have built of this size and portability. Did I mention that this speaker also has blue lights built inside of it that react to sound when switched on? This is a one-time speaker so make sure you get it fast!