It effectively protects areas measuring 1,000 to 10,000sq. Feet. (Depends upon model). After plugging bird repeller in, you will notice a small red l.E.D. Indicates bird repeller is operating properly. Bird repeller unique test button on the panel, when depressed, causes the unit to shift its output down into the audible range of humans for a reassuring check of its ultrasonic output. The shrill, siren-like sound produced simulates the sound pests hear continuously.

Bird repeller devices are meant to keep control of birds. Bird repellers are simple to install as it repels pest birds and highly effective but don't harm humans as its silent to humans ultrasounds waves. Ultrasonic waves are extremely distorted and irritate to birds but safe for humans and eco-friendly to the environment.