Simple remix with a loop added to just the right frame for use with a carabiner. 

This is the right frame only. Print with no supports. 

Use the original Lovely Puzzle Box to print the left frame, key, and lids.  Assemble according to the original instructions. 

Use or print any carabiner of your choice, could also use with paracord or a lanyard, etc.

Do you like my decorative lid? No new file necessary! Print the original lid with an infill setting of your choice and experiment with setting the top layers, or both the top and bottom layers to zero to show the hidden infill pattern!