Hireko Graphite Shaft Extender Shaft extenders fit into the butt of the existing shaft and underneath the grip to extend club length This graphite shaft extenders fits many heavier or thicker walled graphite shafts. The stem portion (or the part that goes inside the shaft) measures 0.485". If the stem is too large, it can be sanded as much as 0.020". Make sure to measure the inside diameter of the shaft first to make sure it will fit. The upper portion that goes above the butt of the shaft measures 0.600". Extends one club