The AC-CSSK2 clamp is the same as the AC-CSF but designed with double cutouts to be more adaptable. It has 200 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, works with any 1" ball and comes with a black knob. Made out of 6061 T6 aircraft-grade aluminum with Type III anodizing . Will work in the harshest of environments, time proven and built to last.