The seller was helpful and exceeded my expectations. I usually only buy online from Amazon.com, but Google's Trusted Stores feature was just as good.
Blower wheel for: 4000 sd/dd/rld, 4001 s
Blower wheel for: 4000 sd/dd/rld, 4001 sd/dd, 4000 rld4/crld4, wc42/47/45/49/50, rwc46/50 & asa/ada/aua 50/5012/51/5112 (16 x 16 3/4 x 1) o/s z4c01b
Buy this part and as many parts as you like and pay only $9.99 shipping, within the Contiguous United States.