How far do cantilever mounts extend?

I just moved to a new house and the only acceptable place to put my 52" LCD is above the fire place. However, there is a "shelf" above the fire place running all the way across the room that is 1ft deep by 6in height. The LCD is 30.5in in height, so from the ceiling to the bottom of the shelf it is 30in; therefore the LCD has so sit at least 14in in front of the wall.


I was thinking about using the Video Secu MW360B 1S2 cantilever mount, but I can't find the specs as to how far it extends forward.

Is there a standard or average that these mounts extend?



Thanks,


Craig