• Fan & blower - Split phase, Dripproof motors • Resilient base motors • Ball bearings (except as noted) • Overload auto • Variable torque on two speed motors • Extended thru-bolts, as noted • Heavy gauge steel frame and base • 48Y and 48YZ frame have 48/56 frame mounting holes • UL recognized and CSA certified • Model 5KH39QN5511X