World’s first audible goose repeller that uses actual alert and alarm calls recorded from geese in the wild. Developed by a noted biologist after 30 years of studying goose behavior and communication. One unit covers seven acres – two units cover up to 21 acres. Ideal for use at golf courses, ponds and parks, schools, hospital grounds, resorts, condo complexes, large estates, or anywhere that geese congregate. Effective against Canada geese.