The Holosun ARO RD2 Red Dot Sight (ARO-RD2-FDE) in Flat Dark Earth is a compact enclosed-emitter rifle red dot sight with a single 2 MOA red dot reticle behind a 22 mm objective, supplied with both a lower-1/3 co-witness mount and a low mount.
ARO stands for Advanced Rifle Optic, and this is the simplest sight in the range: one clean aiming dot, no reticle switching and no solar panel. Red is the most widely used emitter colour and the most economical on battery. Shake Awake switches the dot off when the rifle is still and wakes it the instant it moves, giving up to 50,000 hours from a single CR2032, and the aluminium housing is rated IP67 against water and dust.
How It Compares
The identical sight in black is the ARO RD2 red dot sight in black. Prefer a different reticle colour? See the ARO GR2 green dot sight and the ARO GD2 gold dot sight. For selectable reticles, the ARO MRS red dot sight adds Holosun's Multi-Reticle System in the same 22 mm housing, and the ARO EVO red dot sight steps up to a 26 mm window with Solar Failsafe. Browse all enclosed red dot sights, offset red dot sights and straight-pull rifle optics, or read our guide to choosing an optic for an AR-pattern rifle.
Ideal For
- Civilian Service Rifle and practical rifle shooting on straight-pull AR-pattern carbines
- Practical shotgun and 3-Gun stages, where a single uncluttered dot is quickest
- Rimfire, .22LR and pistol-calibre carbine builds wanting a sealed sight at sensible money
- Airsoft skirmishing and training rifles that live outdoors in British weather
Key Features
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Reticle: single 2 MOA red dot, no reticle switching
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Emitter: compact 22 mm enclosed emitter, sealed against dust and weather
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Electronics: Shake Awake motion activation, up to 50,000 hours from one CR2032
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Illumination: 10 settings — 8 daylight and 2 night-vision compatible
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Mount: lower-1/3 co-witness mount and low mount, both included
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Housing: aluminium housing rated IP67 for water and dust resistance
Technical Specifications
| Optic Type |
Enclosed-emitter rifle red dot sight, 1x (non-magnified) |
| Reticle |
2 MOA red dot (single reticle, no MRS) |
| Objective |
22 mm (enclosed) |
| Illumination |
10 settings — 8 daylight / 2 night-vision compatible |
| Click Value |
1 MOA per click |
| Battery |
CR2032 coin cell, up to 50,000 hours runtime |
| Power Management |
Shake Awake motion activation |
| Mount |
Lower-1/3 co-witness mount and low mount (both included) |
| Housing / Finish |
Aluminium in Flat Dark Earth (FDE), IP67 water and dust resistant |
| Eye Relief |
Unlimited (non-critical eye relief) |
| SKU / MPN |
ARO-RD2-FDE / ARO-RD2-FDE |
What's Included
- Holosun ARO RD2 enclosed red dot sight in Flat Dark Earth
- Lower-1/3 co-witness mount, low mount, CR2032 battery, lens cloth and manual
UK Delivery & Support
Imported from the USA, duty paid by us, and dispatched tracked from the UK — nothing to pay on delivery — backed by UK-based support.
Frequently Asked Questions
Is the Flat Dark Earth Holosun ARO RD2 the same sight as the black one?
Yes. The Holosun ARO-RD2-FDE is optically and electronically identical to the black ARO RD2; the only difference is the Flat Dark Earth finish on the housing.
Will the Holosun ARO RD2 co-witness with AR-pattern iron sights?
Yes. The Holosun ARO RD2 is supplied with both a lower-1/3 co-witness mount and a low mount, so you can either co-witness with standard AR-height irons or sit the sight low on a rail.
What battery does the Holosun ARO RD2 take and how long does it last?
The Holosun ARO RD2 runs on one CR2032 coin cell and is rated for up to 50,000 hours. Shake Awake switches the dot off when the rifle is still and wakes it the instant the rifle is moved.
Is the Holosun ARO RD2 an enclosed red dot sight?
Yes, the Holosun ARO RD2 uses a fully enclosed 22 mm emitter and is rated IP67, so rain, dust and debris cannot reach the emitter and block the dot the way they can on an open reflex sight.
How does the ARO RD2 differ from the ARO MRS?
The ARO RD2 is the single-reticle model, with one 2 MOA dot. The ARO MRS uses the same 22 mm enclosed housing but adds Holosun's Multi-Reticle System, which switches between a 2 MOA dot, a 65 MOA circle and both together as a circle-dot.
Is the Holosun ARO RD2 night-vision compatible?
Yes. The Holosun ARO RD2 has 10 brightness settings, of which 8 are daylight settings and 2 are night-vision compatible, so the dot can be dimmed far enough to use behind a night vision device.
