High efficiency backwardly curved single thickness wheel. Designed air systems, exhibiting non-overloading horsepower characteristics and stable performance over the entire pressure curve. Noise levels are the lowest in the peak efficiency range of the performance curve. Class 3 wheels utilize a circumferential blade stiffener for higher tip speed capability. Sixteen (16) fan sizes from 12-1/4" through 54-1/4" diameter wheels, in Class I, II, III construction.
More Info - See AS 0953 Backwardly Inclined Blower Bulletin