This is a reproduction of Darth Vader's Revenge of the Sith Belt boxes and buckle. It is electronics ready so you can add leds along with a mini switch and batteries. It is made to the correct measurements. I recommend you print all the greeblies in resin if possible so you can make those details pop. You can also print the boxes and back covers with an FDM printer, sand and paint and you are all set. These work with a 2 inch wide leather belt. The buckle is decorative and non functional, you can add some industrial strength Velcro to attach to the belt. Usually the belt closes on the back side and not the front.
The hardware you might need is
4 - 5mm green or white leds
2 - 3mm leds metal bezel like this: https://www.ebay.com/itm/10-Pcs-3mm-Chrome-Metal-LED-Bezel-Holder-Panel-Mount-USA-SELLER/291289879646?hash=item43d23ad45e:g:hmIAAOSw54xUVjrO
2 - 3mm red leds
6 - 330 ohm (or close) resistors
2 - micro switches like these: https://www.ebay.com/itm/Mini-2-Position-ON-OFF-3-Pin-Slide-PCB-Panel-Power-Micro-Switch-SPDT-Microswitch/333947737724?hash=item4dc0d6167c:g:sNIAAOSwZaBgasa9
2 - 9v battery connector like this: https://www.ebay.com/itm/9V-9-Volt-Battery-Connector-Clip-Snap-On-Plug-Long-12cm-Wire-Leads-US/313015060980?hash=item48e126c9f4:g:KvkAAOSwEx5fgQBK