Your site was the only supplier that properly listed this part, so I knew it would fit my MasterBuilt Smoker.
Shaft collar - 1" for residential cooler
Shaft collar - 1" for residential coolers - also fits: ecr4000/4500/5200/6600/7200
Buy this part and as many parts as you like and pay only $9.99 shipping, within the Contiguous United States.