The video simply showed the boom rotating inside the sleeve which was done by hand just to show the mechanics of it. The two bolts to the right of the mast were for tying a rope to and the operator would pull on one rope to rotate the boom one way and another rope to rotate it back. A poor idead really as it means two ropes hanging down from God knows how high and the boom is loose and sloppy in the sleeve. I can't imagine having two ropes hanging from a rotatable array.