I don’t have all the specs on the Alta CB irons, but the weight of the R flex was around 72 rams. I also believe that the “cb” stood for counter balanced. The G400 irons do take a taper tip shaft (.355″). Although there are options, none are specifically counter balanced, but I would not make that a factor. Recoil makes a 65 gram R flex (US0100) in .355 taper tip that is one of the few .355 tip soft, light graphite options. It also comes in an A flex (Seniors) at 64 grams. You might also look at the AeroTech 70CW that is 70 grams and comes in the A and the R flex in .355 taper tip. Both are excellent products.