Wireless Handheld Half-Mile Hailer Kit. Powerful 50 watt PA reverberant horn delivers 108dB sound pressure level, 584-608MHz audio range. Reach crowds up to 3000. Covers the length of a football field! Lets you see and be seen. Great for athletic events, band practice, field days, public safety, law enforcement, outdoor marketing events crowd control, auctioneers, political campaigns, missionaries - any outdoor event. Includes powerful 16 Channel UHF 50W multimedia stereo amplifier with built-in receiver 584-608MHz. and handheld mic with transmitter, extra horn speaker, (2) Compact tripods and carrying case on wheels. Shoulder strap. Power with Optional AC adapter or power up to 200 hours with 10 D-cell alkaline batteries (not included); or Rechargeable NiCad Battery Pack (requires AC adapter).