It is a constant velocity joint, an embodiment of mechanism shown in “Tracta joint 1”.

Yellow swivel and orange one are identical. There are a revolution joints between:

- orange swivel and pink disk.

- yellow swivel and pink disk.

- orange swivel and green shaft

- yellow swivel and blue shaft

Axes of cylindrical surfaces on each swivel are skew to each other at an angle of 90 deg. The video shows the transmission when angle between two shafts is 0 deg. and then 25 deg.