The wheelmark is affixed to devices that have been approved under MED regulations.
Wheelmark
The wheelmark is the stamp in the shape of a rudder affixed to devices approved for use on ships in the member states of the community; European.

The wheelmark is the stamp in the shape of a rudder affixed to devices approved for use on ships in the member states of the community; European.
The wheelmark is affixed to devices that have been approved under MED regulations.