This is the Orgel star-shaped locket from the anime Sailor Moon. Given to Sailor Moon from Tuxedo Mask, this locket plays her theme song. (Or something like that, sorry for errors, not big into the anime specifically). Yes it does open and have an inside, but no space for electronics.
This model is about the size of the hand, comes in two models (Lid and Bottom) and the hinge is designed to put a 0.6mm needle through the holes. Not that the lid has a 1mm hole because in initial printing needle became stuck and broke.
Note: The pictures are of Version 1, the only major change is addition of my maker mark. Please see model for better views
The M74 Maker Mark: This is my maker mark, please feel free to print and use my parts, but please don't sell the models or parts without contacting me first. Also feel free to remix my models.
Print: Make sure you print the model with a large wall and or bottom layer thickness. I found about 5+ layers made the finish much better and had less problems with layer separation.
Update: OCT 10 2018:
-Added Maker Mark
Thanks to Hypertext.za (https://www.htxt.co.za/) for their interest in my model