I wanted to design this remix so multiple colors can be used. One model has a hollow area for the heart, you can leave it empty or print the heart-shaped insert. The insert is a press-fit so it will click into place - just make sure your filament is properly dried first. You can also print the entire thing in one color if you like, a combined STL file is included. The lock bodies print better upside down, the heart looks better that way and the keyhole area looks much better. I added a removable base to the shackle to make it easier to print with better surface appearance. Remove the base once it has printed and insert into the lock body. I use medium viscosity cyanoacrylate for bonding, just a few drops in each top hole then insert the shackle firmly and it fits perfectly. Inspired by my lovely wife.