QuadBlaster QB-4, with 4 Piezo ceramic speakers, projects ultrasonic waves in overlapping fan pattern for 360 coverage. Frequency level irritates birds but is inaudible to humans. Speaker sequencing, frequency, and warble rate are adjustable, making it difficult for birds to acclimate. Unit uses less energy than a 10-watt bulb. Plugs into 110-v. a.c. outlet. Mounts in any direction. Covers up to 6,500 sq. ft. Use in enclosed or semi-enclosed areas, including warehouses, airplane hangars, buildings, and more.