Using the principle of snapping and rolling that I used to play when I was a child, it has a simple physical structure. One end is designed as a cute small dragon mouth. When the mouth bites the line that needs to be stored, the other end will automatically roll back and roll the coil.
The parts include 1. The upper part of the bite joint 2. The lower part of the bite joint 3. The memory metal sheet 4. The outer wrap shell 5. The screw.