1) the line is tied at the center of the beam, on its back side (there's probably an eyestrap) and goes through the supposed rollers and to the cam cleat. As you see one segment only, it looks like 1:1, but when you pull it it turns into a 2:1 system, the second segment appears between the cleat and your hand, so it's as good as the set up with cleat fixed at the beam. I've had both and both work fine.