ARO-CORE (Advanced Rifle Optic Core) is an advancement on our popular 20mm 403 and 503 series optics. ARO-CORE features an all-new 22mm housing design that mates perfectly with our magnifier series and an all-new 1.63” lower 1/3 co-witness pedestal mount. ARO-CORE is available as a 2MOA dot only or with our Multi-Reticle System (MRS) in Red, Green, or Gold.