Safe for birdy bell:
Also the fastener at the top, we used to use those until I spotted my Jardines one day with his toy hanging from his beak. He got it off, then got it clipped onto his beak and the hole near his throat. We have since switched to quick links. He can undo quick links too, don't ask me how, but he can't screw it back together on his beak. I swear, he's a little engineer birdy....