Wonderful vintage blackboard greengrocer shop pricing labels.  The main body of the label is black plastic with a blackboard texture to write on with a revolving orange & red circle at the top to change the measurement - 1KG, La Botte (bunch/bundle) or La Piece.  Each label has a metal spike to attach to the object being sold.
 
A great, fun piece of French vintage.
 
Overall size inclusing spike - W20cm x 18.5