srbecker2384797 wrote an answer about Petzl Trigrest Hand Rest on April 3, 2010
I haven't tried it with aztarex, but tried it with an assortment of tools and axes (including the quarks). The conclusion: except for the Sum'Tec (for which it was designed), it will usually fit on OK but you have to loosen and tighten the bolts with an allen wrench -- you can't lock/unlock the lever and expect it to stay put or move. So that limits it's usefulness if you want to adjust it in the field.
I tried this on the quarks, a standard REI axe, a CAMP nanotech axe, and a BD Raven Pro. I may have tried it on some black prophets, and it probably didn't fit them.