This keychain is made with two embedded 12mm x 2mm magnets, feel free to contact me if you need other magnet sizes. If you want to modify the model yourself you can use the .f3d file.
Remember to pause the print at 2.7mm and insert the magnets. Also make sure you orient them in 2 different ways so the parts hold together when one is flipped.
I recommend printing with 0.1mm layers.
I'll do a version with visible magnets (use glue to hold them in place) as well as a version which doesn't require supports.
I like the rings for the chain to be on one level when the heart is connected so my version used supports (see picture).
The author remixed this model.
My Idea is based on this design, I added magnets instead of clips to hold the 2 parts together.