Like all PING golf clubs, they are meant to be custom ordered to your specifications including shaft, grip texture, grip size, lie, and loft. If you were to get a set of G15s off the rack, they come standard with either the PING AWT steel (Soft R, R, S, and X flexes) or TFC...
The ping way solely just measures on height from finger tip to floor and mainly only adjust loft and lie ping would rathe bend a club 4* then lengthen it, i believe a gold color is 4* upright... the callaway fitting way is impact tape and swinging, with callaway only really wanting...