For everyones reference I took some pics of how the brackets work to hang the above mentioned moving heads.
First is the underside of the unit:
Here is the hardware supplied:
And attached with the loop replacing one of the bolts:
Obviously you bolt your hook clamp to the centre hole on the bracket.
I guess you could directly attach two clamps to the holes in the base using the supplied bolts. The centre threaded hole in the base doesn't seem to do anything
Hope this helps clear up any mystery of the Stairville/iMove brackets