A CNC machined aluminum ball with a 1/4in-20 screw allows it to be compatible with other super knuckle accessories. Can be easily mounted on a camera cage via the 1/4in threaded holes and features a thumb screw for quick locking and for convenient and firm installation. The anti-slip rubber pad at the bottom prevents any scratches. It also comes with a hole for using a #3 Allen key to re-tighten if necessary.