Bigger and Boomier! Unimaginable sheer sound delivered in a compact, waterproof powerhouse. We designed the Rambo Bluetooth speaker for those with an appetite for the outdoor lux. Hosting 4 powerful bass speakers, the Rambo BT Speaker is designed to deliver the most pleasant, balanced and deep base sound for its size. With a battery lasting 15 hours between charges, the Rambo BT speaker comes with a 2 month warranty.