Mounts in any direction to send sound where you need it. Four Piezo ceramic speakers project powerful ultrasonic sound waves in all directions. Made with advanced solid-state circuitry with no moving parts for trouble free operation. Two red diodes indicate rate of warble and speaker sequencing. Contemporary low-profile housing of sturdy durable steel. Four green LEDs show each speaker s sound output. Stop annoying bird pests from causing property damage and costing you maintenance dollars. Eliminate dangerous health and safety hazards. Rid your premises of unsightly bird droppings. Avoid persistent bird infestations with a QB4 bird repeller.