Callaway Golf’s XR Irons re-define speed and distance by utilizing, for the first time in a game improvement iron, Callaway’s 360 Cup Face. The 360 Cup Face allows the entire face to be a hot, to gain distance and increase forgiveness. Callaway also added their Internal Standing Wave to lower the CG and create a Higher MOI in the XR Irons. To encompass these innovations into a game improvement iron the construction needed to be refined to give it speed and a remain functionality, which was achieved by using a two piece construction, and a dual heat treatment, which gave it a stellar look at address.