the instruction be next to incomprehensible , and if you have a projector that only mount with 3 hole , there be no instruction on how to do it -lrb- hint : you have to remove one of the mount arm and re-mount in the center position -rrb- . after I go through all of that , I find that the center pole be attach to the bracket at a angle and I could not loosen it to straighten to a 90 degree angle , and this make it next to impossinble to get it positioned correctly for the screen . this would not have be so bad , but mount bracket also have no yaw control -lrb- horizontal rotation -rrb- , only roll and tilt , which be not good for precise postioning . I end up have to get a optoma bracket -lrb- more expensive -rrb- to mount my hd20 projector .