Holosun ARO-CORE-MRS-GR — Compact Red Dot Sight, Green Multi-Reticle System, 22 mm Window

Overview

The Holosun ARO-CORE-MRS-GR is a compact red dot sight designed for modern rifle platforms — AR-15, PCC, semi-automatic and bolt-action rifles with Picatinny rail. It's the entry point to the ARO (Advanced Rifle Optic) line, positioned to deliver sport shooters and rifle enthusiasts a versatile red dot at Holosun's best price-to-performance ratio.

Its defining feature: a green Multi-Reticle System (MRS) with three selectable configurations — 2 MOA dot only for precision, 65 MOA circle only for fast acquisition, or circle-dot combination (65 MOA + 2 MOA) for the optimal speed / precision compromise. The green wavelength (540 nm) offers high contrast in bright environments, on vegetation and complex targets, while reducing eye fatigue.

The enlarged 22 mm optical window, Shake Awake technology, Lockout Mode, side-loading CR2032 battery (replacement without disassembly), 50,000-hour autonomy and 10 daylight + 2 night vision settings deliver a complete user experience. MAO hard-anodized aluminum housing, IP67 water resistance, 1000G vibration resistance.

Delivered with TWO Picatinny mounts — the 1.63" central mount for lower 1/3 co-witness with AR-15 iron sights, and the 1.05" low mount for bolt-action / precision / hunting configurations — the ARO-CORE-GR-MRS is immediately adaptable to nearly all Picatinny rail platforms. It uses the T1 / T2 footprint, the universal market standard for compact red dots.

Key Features

• Green Multi-Reticle System (MRS): 3 selectable reticles — 2 MOA dot, 65 MOA circle, or circle-dot combination.
• Green reticle (540 nm): superior contrast to red in bright environments, on vegetation or complex targets.
• 22 mm optical window: expanded field of view — faster target acquisition, improved situational awareness.
• Shake Awake: motion-activated on, auto-off after inactivity.
• Lockout Mode: prevents accidental brightness changes during transport or hard use.
• 50,000-hour battery life (setting 6) — over 5 years of continuous use at medium setting.
• Side-loading CR2032: battery replacement without removing the optic — no need to re-zero.
• 10 daylight + 2 night-vision brightness settings.
• Two mounts included: 1/3 co-witness (1.63") + low mount (1.05").
• T1 / T2 footprint: universal standard — compatible with the vast majority of third-party mounts.
• MAO hard-anodized aluminum construction, IP67 waterproof, 1000G shock resistance.
• 1x magnification + parallax-free + unlimited eye relief.

Full Specifications

Optics

• Light source: LED (540 nm — Green)
• Reticle: Multi-Reticle System — 2 MOA Dot, 65 MOA Circle, or Circle-Dot combination
• Magnification: 1x
• Parallax: parallax-free
• Eye relief: unlimited
• Multi-coatings: yes

Electronic Functions

• Shake Awake: yes
• Lockout Mode: yes
• Memory: yes
• Manual brightness: 10 daylight + 2 night vision
• Solar Power: no

Power

• Battery type: CR2032
• Battery life (setting 6): 50,000 hours
• Battery location: side tray

Mechanical

• Housing: aluminum
• Surface finish: MAO hard-anodized
• Color: black
• Waterproofing: IP67
• Vibration resistance: 1000G

Physical

• Window diameter: 22 mm
• Central mount height: 1.63"
• Low mount height: 1.05"
• Weight: to be confirmed with manufacturer

Mount Compatibility

• Direct mount: Picatinny (MIL-STD-1913)
• Footprint: T1 / T2 — universal compact red dot standard (compatible with most third-party mounts: Scalarworks, ADM, GDI, Reptilia, Geissele, Warne, etc.)
• Two mounts included: 1.63" lower 1/3 co-witness + 1.05" low mount

Green Multi-Reticle System — Why This Choice?

The MRS combines three reticles in a single sight, selectable via button press:

• 2 MOA dot only: maximum precision — ideal for shots up to ~200 m, deliberate shots, fine precision. 2 MOA = ~5.8 cm at 100 m.
• 65 MOA circle only: ultra-fast acquisition — the large circle immediately draws the eye to target. Ideal for CQB, dynamic shooting, moving targets.
• Circle-dot combination (65 MOA + 2 MOA): best of both worlds — the circle guides the eye to the target, the dot allows precise follow-up shots. The "donut of death" reticle favored by competitive shooters.

The green reticle (540 nm) offers several advantages over classic red:

• Superior contrast in bright environments — green stands out better than saturated red in full sunlight or on neutral backgrounds.
• Better visibility on light or brown targets — particularly readable on cardboard silhouettes, steel targets, or urban backgrounds.
• Enhanced human eye sensitivity — the human eye is more sensitive to green than red → dot perceived as brighter at equal electronic intensity → energy savings and less eye-dazzling in prolonged use.
• Reduced eye fatigue — more comfortable wavelength than pure red for long sessions.

Use Cases & Context

• Dynamic sport shooting: IPSC, USPSA, 3-Gun, PCC — compact + MRS + 22 mm window combination for fast acquisition, with 65 MOA circle for close targets and 2 MOA dot for distant ones.
• Short/medium-range precision sport shooting: up to ~200 m in dot-only mode, extendable with a Holosun HM3X or HM5X magnifier.
• Semi-automatic rifle platforms: AR-15 in 5.56 NATO / .223 Rem, PCC in 9x19 — 1.63" co-witness mount suited to AR-15 iron sights.
• Bolt-action / precision rifles: 1.05" low mount for Picatinny-rail bolt-action, hunting, Field Target sport.
• Stand and stalking hunting: green reticle particularly readable in forest environments or on variable-contrast targets. Compatible with big-game hunting when using appropriate .308 Win / 7.62 NATO caliber.
• Service and patrol shooting (professional use): patrol rifle platforms — IP67 and 1000G suited to standard service constraints.
• Modular configuration: universal T1/T2 footprint = wide choice of premium third-party mounts (Scalarworks LEAP, ADM Recon, Geissele Super Precision, etc.).

ARO CORE vs ARO EVO — Which to Choose?

The Holosun ARO range comes in two lines:

• ARO CORE (this version): accessible line — 22 mm window, IP67, no Solar Failsafe. Ideal for a first premium red dot at a controlled price.
• ARO EVO: high-end line — enlarged 26 mm window, reinforced IPX8 waterproofing, integrated Solar Failsafe, automatic brightness adjustment. For shooters seeking maximum ruggedness and features.

Both lines share the T1/T2 footprint, side-loading CR2032 battery, Shake Awake and included dual mount — you stay within a coherent ecosystem.

Holosun Magnifier Compatibility

The ARO-CORE-GR-MRS is compatible with Holosun flip-to-side magnifiers:

• Holosun HM3X — 3x flip-to-side magnifier for range extension up to ~200-250 m
• Holosun HM5X — 5x flip-to-side magnifier for range extension up to ~300-400 m

About Holosun

Holosun has become one of the major players in tactical and sport optics worldwide. The brand combines advanced technologies (Multi-Reticle System, Shake Awake, Solar Failsafe, partner ACSS reticles) with exceptional value, adopted today by many sport shooters, hunters and professional units. The ARO (Advanced Rifle Optic) line is the brand's dedicated rifle platform — the ARO-CORE-GR-MRS is its compact version with green Multi-Reticle System.

What's Included

• 1 Holosun ARO-CORE-MRS-GR optic
• 1 CR2032 battery
• 1 Picatinny central mount 1.63" (1/3 lower co-witness)
• 1 Picatinny low mount 1.05"
• 1 microfiber lens cloth
• 1 Holosun multi-tool
• 1 wrench
• 1 user manual