It is a retractable bracelet designed for 3d printing. Resin is the preferred material when printing. To assemble parts together, you may need to sand some parts or add some glue on parts,depending on the 3d prints quality.
It is gear type. When you drive the "clock", it can extend or retract. The inner hole is diameter 70mm.
Note:The 3d prints' quality is important to make it run well.
STL format files are included. If you need STEP format files, please visit [https://www.twothreed.com/](http://)
video:[ https://youtu.be/G_EPVLYeO0E](http://)