Bird B Gone MMSONIC-SP2 Extra Speakers for Super Sonics Bird Repellant For use with the Bird B Gone Bird Chase Super Sonic or Goose B Gone Super Sonic Bird Deterrent Units Each speaker set provides two additional acres of coverage increasing coverage from 1 to 3 acres. Weatherproof. Easy to install, simply plug into desired sonic unit. Each speaker includes 50 ft. of speaker wire Up to 4 speakers can be added to each sonic unit increasing coverage to 5 total acres