The third French Adrian model 26, is this complete and green helmet. The RF stands for République Française. The rust on top of the comb tells us this comb is made of iron. The comb ends in a point, so base on the information from: http://world-war-helmets.com/fiche.php?q=Casque-Francais-Adrian-Mle-26 This helmet can be made by: Carpentier, Franck or Japy. Let me know if you can tell me who made this helmet. By zooming in on the liner stamp I found out this helmet is from 1938.