Fire Extinguisher Ball Holder // Pegboard X Mount
This is a pegboard mount for holding an AFO Fire Extinguisher Ball (Amazon; eBay)... that said it should be able to hold other spherical objects around 115mm in diameter just fine!
Designed for pegboards with a 1 in. hole spacing, and 0.25 in. holes.
For a critical part like this, it's probably a good idea to use a quality filament and high shell count, if not a solid print. I like MatterHacker PRO PLA, though I assume PETG, ABS, and other less brittle materials could hold up even longer.