Patented Universal RAI-J� WHISPAIRTM blowers are heavy duty rotary units in a compact, sturdy design, engineered for continuous service when operated within speed and vacuum/pressure ratings. The basic model features a cast iron casing with a computer-designed cast relief for noise and shock suppression, carburized and ground alloy steel spur timing gears secured to steel shafts with a taper mounting and locknut, and cast iron involute impellers. Oversized anti-friction bearings are used, with a cylindrical roller bearing at the drive shaft to withstand V-belt pull. Detachable rugged steel mounting feet permit easy in-field adaptablility to either vertical or horizontal installation requirements. The Universal RAI-J� incorporates grease lube on the drive end and splash lube on the gear end. ROOTS� exclusive �figure-eight� gearbox design improves oil distribution to maximize bearing and gear life.