The Quad Blaster Pro is a full-featured ultrasonic bird control system that gets rid of stubborn bird infestations with a Silent to Humans audio attack. This automated sound system uses four internal speakers to emit high frequency sound waves and audio signals. The QB-4 is an electronic oscillator tuned between 22 and 30 kHz, beyond the range of human hearing, but perfectly audible to birds and other pest animals. The sounds are designed to confuse, disorient and intimidate pest birds to quickly scare them away from the effective area up to 6,500 square feet. The intense ultrasonic sound is measured at 112 dB, nearly equivalent to a jet airliner taking off. Birds will not linger while exposed to this sound.