I'm rather disappointed with this product, and I wonder if 3 arms is 2 arm too many. Unlike other reviewers here (and on other websites) for this product, I'm not at all happy with the ability of this to manage even the lightest of loads. No matter how hard I tighten the bolts, there is always an immediate sag when a minimal load (e.g. iPad or even a small LED light) and a gradual drop of the arm over time. I have tried various configurations to mitigate this, but with no success. At best, it can suspend my mobile phone (with the Manfrotto 143BKT) but not much else.
Your mileage may vary.
Having said that, the arms and joints feel sturdy - I don't fear they will break, just not hold their position.