The outer tooth count will have 20 teeth and you will have to count the smaller inner tooth count to verify you order the correct replacement gear.
Gear and Pod Style
Once you determine the tooth count of the smaller gear you will need to match it with the correct size pod which you will also need to count the teeth on. 15 tooth gear with small pod // 20 tooth gear with medium pod // 25 & 26 tooth gears with large pod
Three Gear Style
The first gear will have 12 teeth, the second will have 48 teeth on the outer portion and then between 12 and 21 teeth on the smaller inner gear which you have to count to verify you order the correct replacement set.