Michelin have made several versions of this sign over the years. The first version had a red background and then they were updated in the late 70’s to blue. This particular sign has somewhat different to many in that it has underneath the currently visible signs 2 other signs. It would seem that the sign was updated at some stage with new images. What the images are underneath is unknown although it is possible to see the outline and I believe they are much the same with Mr Bibendum sat astride his motor bike. Also note that each side shows a different motorcycle.
The sign measures 18 3/4 inches square (47cm sq) and is made of alloy.