This replacement ferrule was specially designed to fit the original Callaway RAZR-Fit Adapter. Works on Rogue, Epic, Big Bertha Fusion, XR16 driver, Big Bertha V series driver, Big Bertha XR driver, Big Bertha GBBII driver/fairway, Big Bertha Alpha 816 driver/fairway X2 Hot driver, 2014 Big Bertha driver/fairway, Big Bertha Alpha driver RAZR Fit extreme driver/fairway, X-Hot driver. Ferrule fits a 0.350″ shaft.