The entire belt clip is plastic. It does have a swivel and it will pop off your belt, it's happened to me more than once. And plastic breaks in time.
Ditto here. Broke mine first. The little tabs that hold the swivel in place. The wife gave me hers as she just carried it in her purse. Popped the clip off the swivel on it a couple of weeks ago. I did mount it to the triple tree and now have a place to pop the otter box clad iPhone onto the bike. I'd mounted a 12V adapter, so I can use it as a GPS navigator (app = Navagon $15.00) while listening to my tunes with a blue tooth stereo head set.