Multiple-disk clutch.
The orange shaft and the yellow cylinder are driving. The two orange outer disks are slidingly splined in the yellow cylinder.
The green shaft is driven. The blue part and the two green inner disks are slidingly splined on the green shaft.
The clutch is connected by the spring force which presses inner disks and outer disks together through the blue part (manual force is possible).
Positioning device for the white lever at the clutch’s disconnected position is not shown.