It's a multi-lobed rod that rotates to open the inlet and outlet valves to the engine. The 600cc, 700cc and Roadster Camshafts are interchangable. Putting a roadster camshaft into a For2 increases the engine power.
I'm sure at some stage there will be a how2 change your camshaft but not now.
This is just for comparison as I get hold of them to measure.
At the moment I am unsure as to whether this is a standard Roadster cam,
Brabus Roadster or Brabus 101 Roadster cam. There may not be a difference.
The lobes are (according to my cheapo digital calipers) 40.45mm at the widest part.
This suggests that the other cams have the same lobe angle and height,
the difference is the shape of the lobe. The rise and fall is quicker on the Fortwo cam.
In this case, the lobes are just short of 120 degrees.
0 - 120
120 - 240
240 - 360
Which completes the full rotation and creating a 3 cylinder cycle.
The smart engine fires in a 1-3-2 pattern, to be more specific,
Although classed as a 120 degree rotational cam, the 3 grouped pairs...
1 in - 2 out
3 in - 1 out
2 in - 3 out
... are not exactly level to each other on the shaft with about 1 degree difference.