One of the goals of the gearbox was to reduce it’s footprint, and that includes the space it takes to install and remove it. To that extent the output shaft is split into two parts, half in the gearbox, other half in the sprocket and wheel. This allows the gearbox to be removed after pulling it only 5/8 of in inch into the robot, instead of the 2-3 inches that would be required otherwise.
More specs,
two speed shifting 17fps and 6fps
Cim to cluster shaft is 3mm GT2 Belt
and yes, there is a bevel gear in there.