This is a candle wick holder for folks who make soy or container candles. I bought some of the ones on Amazon, but they didn't work for larger containers, so I fired up Tinkercad and made my own. Individually, they're large enough to span most small containers, but you can print multiples and snap them together to span pretty much any size container.

I printed mine at 75% infill just to give them some strength, but I think you'd be okay down to about 30% if you weren't going to use them that often. They take about 30 minutes each to print, varying by infill.