I echo punkie's comments exactly. I had to sand down the hinge parts to get it to slot together and ream out the bolt hole a little bit to get the screw to slide through. The only other issue I've had is that in aggressive flips and rolls the angle slips and no matter how snug I tighten the bolt the angle doesn't stay locked in. It works flawlessly for fast forward flight and turns and being mounted on the vibration balls keeps the footage very smooth.
I was a little bit worried about the print material as it feels pretty flimsy, but it has survived many, many crashes without any problems.
Overall I'm happy with the purchase.