The mast rotator system most of us use and I believe your seeing in the Murrays catalog is very simple but effective when setup properly. I'm not sure how to attach a picture so I will try to describe it. First the rig has to be loose enough for the mast to rotate freely to about 10 degrees forward of the beam. A light line is tied to the end of the rotator arm, run around the front of the mast through a micro block and tied to the rotator arm on the other side. This loop is pulled forward by a length of shock chord ( I use 1/4" ) which is looped from one bridle adjuster through the micro block to the other bridle adjuster. The tension in the shock chord pulls on both sides of the loop of line attached to the rotator with equal force but as the mast rotates one side wraps around the mast while the other side pulls on the extended end of the rotator arm. The longer lever arm provided by the rotator arm causes the mast to rotate. You may have to play with the tension in the shock chord some to get it working right but once you have it right it works great and you never have to touch it while sailing...Dan