Amplivox SW610A 50-Watt Wireless Half Mile Hailer 50W wireless multimedia stereo amplifier with built in 16 Channel UHF receiver; 584-608MHz Outdoors. carries sound the length of a football field. Reaches crowds up to 3,000 Lapel & Headset Mics with body pack transmitter Power with S1460 AC adapter or power up to 200 hours with 10 D-cell alkaline batteries (NOT INCLUDED) or S1465 Rechargeable NiCad Battery Pack (requires S1460 AC adapter) Reaches audiences up to 3,000 Weatherproof horn speaker carries sound the length of a football field 50W wireless multimedia stereo amplifier with built in receiver Wireless lapel and headset mic with body pack transmitter Shoulder strap for easy portability