RECOMMEND MAKING IN ABS (PETG can work too, but the tougher the material, the better. You can use PLA, but I would NOT recommend it.)

Protect your $300+ optic with this custom-designed killflash for the Olight O-sight RMR for airsoft pistols.
This helps reduce glare in both indoor and outdoor settings without compromising the sight's functionality. The killflash has also been methodically designed to not prohibit or create complications with the side buttons, allowing the existing easy access to remain, well, easy!

15% infill works fine, but if you want to increase it, that's fine too. Due to the size, the infill won't make a huge difference structurally.

PLEASE NOTE: this optic (printed in ABS) can handle being shot, on average, 2 times before being fully broken. See end photo's for results.