The toothed adapter is designed to protect your Smart Lock. When excessive manual force is applied to the knob, the Smart Lock could be damaged. Therefore, if the adapter breaks, it has fulfilled its protective function.
Please contact support to receive a new adapter free of charge.
Once you have received the new adapter, make sure you insert it with the protruding side first.
Note on improved adapter:
We are constantly refining the adapter based on user feedback. The latest version of the adapter is much more stable and less likely to break, while still protecting the Smart Lock.