The AC-CSF-KG clamp was the first to be designed using the standard knob you see today. It has 30 degrees of side to side movement and measures 1 1/2" between the centers of both ball mounting holes. Uses a 1/4"-20 coarse thread bolt and works with any 1" ball. Comes with a green knob which can be useful in the cinema industry for color-coding camera rigs. Made out of 6061 T6 aircraft-grade aluminum with Type III anodizing and Type ll for the knob. Will work in the harshest of environments, time proven and built to last.