The unique BA-55 provides self-contained, high-quality, and battery-powered sound reinforcement for any environment. It’s solidly built yet lightweight, and comes bundled with a matching wireless microphone for public speaking, singing, and many other events. Use the BA-55 as a small wireless PA system in school classrooms, business meetings, restaurants, weddings, intimate music venues, and more. In a cool and convenient twist, the BA-55 contains an internal accelerometer sensor that automatically switches operation between stereo output (when positioned horizontally) and mono output (when positioned vertically). If you’re speaking and need maximum power and projection, use the vertical mono mode. For wide musical spread, turn horizontal. It’s that easy!