These are the planetary gears for the Autohelm 4000 and ST4000 motor gearbox (part 4 in the parts diagram above). This is a set of 11 gears. The gearbox contains a total of 22 gears. If you need all the gears, order 2 sets. Note these gears are for the 2.0 mm shafts (some rare versions of Autohelm autopilots have 2.5mm shafts, so make sure you check this before ordering).
These gears are for the Mark I BLACK wheel Autohelm 4000 and ST4000 - they DO NOT fit the Grey MK2 wheel. Find the MK2 gears here.
Download the installation instructions for the gears here.