This was made for a Panto in the UK,

There is space inside the hollow gem to take two led's in series I chose to salvage a couple of white ones from a cheap torch/flashlight.
All of the parts should fit together as shown in the pictures.

The part labelled switch stopper is optional and simply prevents the switch pushing back inside the ring body when the button is pressed.

The battery contacts are simply made from the legs of a capacitor quite thick, 0.8mm 0.03in and should be bent to fit, with a slight hump where the contact with the battery is made, I think the pictures show this.

The wires can be super glued in place as should the non contact parts of the battery contacts.

I found the best orientation for the batteries was positive down and is wired accordingly.
Ignore the orientation of the batteries in the picture with the ring showing IKEA on the top, they should be IKEA side down.

I used a switch salvaged from an old monitor control panel, you may have to find something similar, The printed power button simply glues onto the switch when it is place.

The printed layer immediately above the switch may not print at all, it's very thin, but is not important.

The ring takes two CR 2032 batteries in a slide out tray. The tray has a small angled groove on top to allow you to get a grip on the battery tray.

I found that putting the batteries in backwards by accident seems to do no harm to the led's

I covered my LED's with a see through red sweet wrapper.

Coloured LED's should be an option, just be sure not to overload them if they cannot take 3v each.

Important note!!:- The battery assembly will provide 6 volts, so make sure the combination of LED's you use can handle this.

I used a natural PLA filament for the gem and gold for most of the rest of the parts.
I would recommend a 0.1mm layer height for most parts. I'll leave you to make your own choices with the rest of the settings.

This is quite a big ring, and the switch I used was intended for manual operation.
You could feed wires into the ring through the switch hole if you wanted to use an external battery supply.
Enjoy!

Shameless plug, Ikea sell these CR 2032 very cheaply, about £1 for 8 in the uk.