A little box with a secret hatch. To unlock it, you must push the button and return the box to extract the part named "fond". I will upload a new part with 2 springs holder. It's easiest to open it, but we have smaller compartement.You must add a spring and a headless screw. I have designed it for de valentin's day and i craft it in aluminium and copper alliage with a 3 axes turnning machine. GL to print it, i hope you enjoy !