Amplivox SW223 Wireless Handheld Audio Portable Buddy Audience Size: up to 1000 people Runs up to 200 hours with 10 D-cell alkaline batteries (not included), or use the optional rechargeable AmpliVox S1465 NiCad battery pack with S1460 AC adapter/recharger Built-in 6" x 8" Jensen design speaker, 50 Watt multimedia stereo amplifier 16 Channel UHF Wireless Handheld Microphone. For audience size up to 1,000 For rooms up to 10,000 sq. ft. 50W wireless multimedia stereo amplifier with built in receiver Wireless handheld mic with built in transmitter