Lightweight and strong straight back axle construction for XRAY XII features a super-light and tough graphite shaft that's specifically machined for perfect stability and smoothness. The threaded shaft is specifically embedded in the end of this graphite axle. The CNC-machined aluminum mounting dish is precision-pressed on the axle and it is aligned and pinned to put it sturdily and perfectly in position. The entire installation is completely balanced with zero run-out for vibration-free operation.