If you need to be heard in a crowd, this is a great way to do it. Totally portable using 8 x c batteries not included for approximately 8-hours of operation. The powerful 25w amplifier and horn speaker will help your message be heard up to 500m away! the microphone can detach from the back of the unit thanks to a curly cable, allowing you to hold the unit above your head in a crowd, but still speak clearly into the microphone. A built-in siren generator is also included, which is sure to get you attention. The shoulder strap makes it easy to carry and trigger activation provides straight forward operation and power-saving while not in use. Features - detachable microphone - siren generator - shoulder strap - max output power 25w - microphone uni-directional dynamic width 240.0mm height 270.0mm depth 355.0mm weight 1.45kg battery used for main product size shape c battery quantity 8.0pc batteries included false batteries can be replaced by user true compartment location back runtime 6.0hr general type of item personal alarm personal alarm activation method button power output 25.0w bullhorn function false external microphone true built in torch false megaphone range 600.0m