For the last three weeks, CNET has been stress testing the iPhone Duo's hinge on a livestream. After over 451,000 folds, the hinge is showing signs of wear. CNET says the hinge started feeling looser at the 390,000-fold point, and by 440,300 folds, there was enough of a shift in the mechanism that the screen didn't open in full before the machine closed it again, and there was no distinctive snap. It is 5 to 10 degrees from the fully open state and can be opened fully by hand.

For the last three weeks, CNET has been stress testing the iPhone Duo's hinge on a livestream. After over 451,000 folds, the hinge is showing signs of wear. CNET says the hinge started feeling looser at the 390,000-fold point, and by 440,300 folds, there was enough of a shift in the mechanism that the screen didn't open in full before the machine closed it again, and there was no distinctive snap. It is 5 to 10 degrees from the fully open state and can be opened fully by hand.