Avlink Mini Waistband Megaphone.Voice Amplifier SR-050 With Microphone Low Feedback Noise, Hi-Fi Performance, Microphone Included Perfect for Classroom, Auditorium, Meeting Room, Church SPecial Presentations and much More! Device has "AUX" funtion for radio to enlarge power output Use with Rechargable batteries (Batteries NOT included) This device has charging function, please use with RECHARGABLE batteries