This air blower is a powerful and efficient tool for quickly and easily drying wet surfaces. It features a high-powered motor that produces a strong airflow, allowing you to quickly dry large areas. It is lightweight and easy to maneuver, making it ideal for both indoor and outdoor use. It
From Wikipedia
The Roots blower is a positive displacement lobe pump which operates by pumping a fluid with a pair of meshing lobes resembling a set of stretched gears. Fluid is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust.