Bluetooth® Mega Hailer PA System The AmpliVox Mega Hailer Mobile PA System is a 50-watt, totally wireless, highly intelligible, lightweight rechargeable battery powered loudspeaker system for general PA applications in areas that are not equipped with a PA. The horizontally aligned horn broadcasts crystal clear voice announcements and reinforces sound to make it louder to audiences over large wide areas. Built-in Bluetooth® module allows you to wirelessly stream sound from any Bluetooth® capable device. The system includes an AC power-cord for continuous operation when connected to a standard AC wall-outlet, and facilitates charging the included internal sealed lead acid (SLA) batteries. On a full charge, the system will operate up to ten hours on its SLA batteries' power. During emergencies, the battery powered design sets up quickly and allows you to broadcast emergency information even during power outages.