Callaway Japan has released 3000 sets of the X Prototype forged blade for the Japanese market. Designed by Roger Cleveland and forged from soft S20C steel by Endo, the Japanese version of this iron feature lofts 1* stronger than the US version and DG S300 or M10DB Uniflex (SR) steel shafts. I'm not sure of the number of sets being sold in the US but apparently they are being sold as Tour Authentic irons. In Japan they are considered retail but limited to 3000 sets.