My friend Kevin sent me a couple of flexible LED strings, so I designed a pair of finger rings for my wife.
It's a great party conversation starter.
The design is based on a 300 mm long flexible "rope/string" type LED.
The 3D printed ring has an inner diameter of 19 mm (0.748"), which is close to US / Canada ring size 9.
Inner circumference is 59.66 mm (2.35").

Designed in FreeCAD. I've kept the pitch a bit wide to spread out the helical coil.
Pretty much everything is published here, but there's also the repo on Github at
https://github.com/wyolum/LED_finger_ring/wiki

Print Settings

• Printer brand: ELEGOO
• Printer: ELEGOO NEPTUNE 4 Pro
• Rafts: No
• Supports: Doesn't Matter
• Resolution: 0.2
• Infill: 15%
• Filament material: PLA
• Filament brand: Generic
• Filament color: Black