QuietComfort 35 I II Metal Hinge Swivel as Same as The OEM QC35 Hinge Replacement Parts Accessories Compatible with Bose QuietComfort 35/QuietComfort 35 II/QC35/QC35 II/QC45/QC25 Headphones (Black)

This is a nice alternative to paying Bose $300, but I warn it is no easy task. If the left side broke on yours it's easier, few less steps. The right side is a nightmare. You have to de-solder the leads on the main wire so you can pull off the old hinge and slide on the new hinge from this kit. Then you have to solder them back on in the correct configuration. These wires are tiny and you're soldering them directly to the board. You also have to navigate a lot of hardware, and on the right side you have to use a heat gun to take off a glued panel to access the leads. Fix at your own risk.

You have to go on their site and get tthe indepth guide to solder back the wires. This repair is not for any novice. As the wires are tint and there are many of them.