In reply to Greasy Prusiks:
Never seen one before either, but with folding design's; the fold is a good place to bust your angle. A way to prevent that is to have velcro that connect the two sides, so it's less likely for your foot to end up in the fold or things pocking up the fold from the other side. (angled folds or taco's are ambious other solutions to the same problem)
Can;t see it on the image, but does not appear to have it. (most cheaper folding designed don;t)