^ Bryson just installed one of those on his buggy.
Indeed I did...
I have a 2.5(?) pounder mounted on it now, and it is nice and sturdy. I have an 8lb one that I mounted on it to test it out, but it seemed a bit much. Not that the mount wasn't up to the task, but more that I didn't trust 2 hose clamps to hold up to the 11lb (actual weight) extinguisher with me driving...
I think they're backordered from Poly though... when I got mine, there were only a couple right hand release mounts remaining, and no lefts.
Neat mounts though!