Demos we have -

King Cobra F7 "One" 5 - GW  Regular steel shaft  (same length shafts)

King Cobra F7 "Progressive" 5 - GW  Stiff steel shaft (1/2" increments)

Rickie Fowler

Make sure to check out the video below for a great explanation of their iron design and why "One Length" irons can work for you. 

Bryson DeChambeau

5 iron                                  7 iron                                   9 iron                                    Gap Wedge

Most tour players like Rickie play progressive length clubs.  We are not all tour players. Choose the club that's best for you!