Update date: August 9, 2021: Thanks to Jay Seery for providing the STL files of each independent component.

This model was not designed by me. The model was originally posted on GrabCAD, and I believe many friends, like me, will find it quite practical. So I'm sharing it here. The original author is Josh Scheringer. You can simply search for "3D Printable Latch V3" on GrabCAD to find his design.

Here is the project description he posted on GrabCAD:

"Alright, all the details have been adjusted in place. This is the third time I've released this design. The 3D-printed locking buckle features a 0.6mm gap design, which effectively prevents parts from sticking together due to welding. Although I haven't conducted actual printing tests yet, I've checked it multiple times and believe it's ready for safe use. When printing, please use the EZ Print.stl file - in the STEP format file, there are no gaps between the marble and the base, or between the locking buckle and the hook. This

I am currently printing on the Ultimaker 2+ printer, and I will share the final printing results and user experience with you all in the future.