Valcom 3 Horn Speaker Paging Mass Notification and Emergency PA System Kit (Commercial Grade) Standalone PA (Public address) System. Covers up to 12,000 Sq. ft. PER SPEAKER (6,400 sq. ft. for moderately noisy environments PER SPEAKER) Up to 116 dB measured at 4' Expandable with additional Horns or Ceiling Speakers. Microphone is Omni Directional Push-to-talk with switch & locking bar for Desk Paging High-Quality rugged design that is weather resistant for indoor/outdoor use, BUILT-IN 5 WATT AMPLIFIER MODULE, BUILT-IN VOLUME CONTROL, OMNI-DIRECTIONAL MOUNTING BASE, WALL OR ELECTRICAL BOX MOUNT, I-BEAM CLAMP INCLUDED MADE IN USA, ready to connect. Cable sold separately but no additional parts necessary for full operation.