oldiebutgoodie
Apostle, Church of Vaporization
http://www.delta.com.tw/product/cp/dcfans/download/pdf/BFB/BFB40x40x10mm.pdf
BFB0412HA
Not sure if you can order straight from delta, and if so I wonder if Arizer has made any changes to the design.
BCVapo - You could also try removing the fan, removing the sticker, and putting a few drops of oil in the bearings.
I had forgotten that the fan model was changed to one that is encased. You might try compressed air or turning the blades by hand lest debris has somehow gotten lodged inside. I can't determine if the bearing is accessible with this design. I found it avail at pchub.com.