Mandatory slot gap spacers
Flexing and stalling wings have been a hot topic in F1 this year. While Ferrari and BMW were asked to strengthen their rear wings, some of the designs also feature a movable wing so that the slot gap between the two horizontal elements gets closed and hence makes the wing stall. In order to prevent these performance gains, the FIA mandated slot spacers that prevent the gap to be closed. It is for all teams a carbon element that connect to both the upper and lower element and makes their relative position fixed.
Interesting solution: the spacer position and design contribute to minimize vortexes. I would have put the spacer between the two wings, probably spoiling some of the downforce.
The spacer seems pretty thin. I wonder if there is any chance to move laterally on curves and close the gap anyway (if the wings are curved).