This 8" Detachable Ball to YS Mount Arm is equipped with a standard 1" diameter ball joint on one end and a standard YS connector on the other for attaching a strobe or video/focus light. The ball-joint end fits into the UXCLM-1 Clamp or other clamps for 1" balls, which are available separately. Such a clamp will allow you to connect the arm to a ball-mount base on an underwater camera tray or grip handle, or to another ball-jointed arm. The arm consists of 2 separate parts, and the part with the YS end slides out from inside of the one with the ball mount end when you press the quick-release button. This allows you to hold your strobe or video light at a higher position or a different angle for a particular shot, and then slide this half of the arm back into the other one to return to your normal setup. Built for durability, the lightweight Detachable Ball to YS Mount Arm is made of fiberglass-reinforced plastic, so you need not worry about rust.