This is an ARD or anti-reflective device otherwise known as a “killflash” for an Aimpoint Acro P2. 

A killflash is a device designed to reduce glare and reflections from the lens of a firearm’s optics, such as scopes or red dot sights. It typically consists of a mesh or honeycomb-shaped structure that attaches to the front of the optic. Its primary purpose is to prevent light from shining off the lens and revealing the position of the shooter to enemies or bystanders. This can be especially important in tactical situations, where stealth is crucial. Additionally, the killflash helps to reduce lens flare and enhance sight clarity by limiting stray light entering the optic.

Installation is as simple as sliding it on from the top in the groove behind the objective lens until you reach a snap fit.

For best results I recommend printing at .12 layer height in ABS-GF however a matte PLA will work just fine. This is my first model I created myself, if you like what you see give me a thumbs or a boost would be greatly appreciated!