This is a US-spec shaft for the TaylorMade Mini Driver BRNR. While the appearance (model) is the same as the Japanese model BRNR shaft, the Japanese model has a frequency of 244 cpm, whereas the US model has a frequency of 256 cpm, a difference of about two flexes. If you found the Japanese model a bit too soft, or if custom shafts feel too stiff, please give this a try.