You can confirm the number of teeth on the pulley by counting them. I know too simple an answer...
608 bearings measure 8mm ID, 22mm OD, and 7mm wide.
624 bearings measure 4mm ID, 13mm OD, and 5mm wide.
608 bearings are extremely cheap (~$1/ea) and available everywhere in the world. The 624's may work on the YZ plate, but to use the double precision portion you need the 22mm OD. Now you could print up a sleeve to put over the 624 bearings to increase their OD if you were so inclined.