Thanks for checking out the QB-4. The QB-4 is an ultrasonic bird repeller that is generally used indoors or in semi-enclosed spaces. The unit itself has four separate speakers to give it an omnidirectional coverage. It covers roughly 6,400 square feet and it's used for practically any bird. The great thing about the QB-4 is that it's silent to humans bud birds absolutely hate it so if you have a warehouse space where people are working, it's not going to hinder your daily activity but yet it's still going to reroute the birds silently.