The Holosun HE512T Red Dot Sight (HE512T-RD) is a 1x fully enclosed rifle red dot sight in a Grade 5 titanium housing, with the Multi-Reticle System — a 2 MOA red dot, a 65 MOA circle, or both together as a circle-dot — behind a 0.91 × 1.26 in (23 × 32 mm) window, on an integrated Picatinny mount at 1.41 in (35.8 mm) absolute co-witness. UPC 605930624748.
The enclosed housing is the argument: on an open reflex sight, rain running down the glass or mud thrown up from a wet firing point sits directly in front of the emitter and smears the reticle. On the HE512T the emitter is sealed inside titanium, so the dot stays clean in weather that defeats an open optic. Solar Failsafe backs up the side-tray CR2032 for up to 50,000 hours, adjustment is 0.5 MOA per click with ±50 MOA of travel, and the whole unit is rated IPX8 at 9.17 oz (260 g).
How It Compares
The green version is the HE512T green dot sight. For an open-emitter sight with the same reticle set and window, the HS510C red dot sight is the classic choice. For a smaller enclosed rifle optic, the AEMS Macro red dot sight is lighter. To add magnification behind it, fit the HM3X 3x flip-to-side magnifier or the HM3XT titanium 3x magnifier. Browse all Holosun rifle red dot sights, every enclosed red dot sight and our shotgun red dot sights.
Ideal For
- Civilian Service Rifle and practical rifle on straight-pull AR-pattern carbines
- Practical shotgun and 3-Gun, where the 65 MOA circle drives fast close hits
- Wet, muddy British field and range conditions that defeat an open emitter
- Pistol-calibre carbines and rimfire rifles running a Picatinny rail
Key Features
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Housing: Grade 5 titanium with a fully enclosed emitter, IPX8 rated
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Reticle: red Multi-Reticle System — selectable 2 MOA dot, 65 MOA circle, or circle-dot
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Emitter: 650 nm red LED
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Window: 0.91 × 1.26 in (23 × 32 mm)
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Mount: integrated Picatinny mount at 1.41 in (35.8 mm) absolute co-witness
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Electronics: Solar Failsafe supplemental power plus Shake Awake motion activation
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Battery: side-tray CR2032, up to 50,000 hours of runtime
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Adjustment: 0.5 MOA per click, ±50 MOA windage and elevation
Technical Specifications
| Optic Type |
Enclosed rifle red dot sight, 1x (non-magnified) |
| Reticle |
Multi-Reticle System — 2 MOA dot / 65 MOA circle / circle-dot |
| Reticle Colour |
Red |
| Light Source |
650 nm red LED |
| Window Size |
0.91 × 1.26 in (23 × 32 mm) |
| Mount |
Picatinny, 1.41 in (35.8 mm) absolute co-witness |
| Battery |
CR2032 in a side tray, up to 50,000 hours |
| Power |
Battery with Solar Failsafe supplemental power |
| Click Value |
0.5 MOA per click |
| Adjustment Range |
±50 MOA windage and elevation |
| Housing |
Grade 5 titanium |
| Water Resistance |
IPX8 |
| Dimensions |
3.35 × 1.63 × 1.7 in (85 × 41 × 43 mm) |
| Weight |
9.17 oz (260 g) |
| MPN / UPC |
HE512T-RD / 605930624748 |
What's Included
- Holosun HE512T-RD enclosed red dot sight with integrated Picatinny mount
- Multi-tool, lens cloth and user manual
Warranty
Covered by Holosun's manufacturer warranty, handled in the UK by Xtreme Tactical.
UK Delivery & Support
UK-stocked and dispatched tracked from our UK warehouse — no import duties or customs delays — backed by UK-based support and Holosun's warranty.
Frequently Asked Questions
Does the Holosun HE512T need a separate mount?
No. The Holosun HE512T Red Dot Sight mounts directly to a Picatinny rail on its integrated mount, which sets the reticle at 1.41 in (35.8 mm) absolute co-witness. No additional riser or mount is needed on a standard flat-top receiver.
What does absolute co-witness mean on the HE512T?
At the 1.41 in (35.8 mm) height stated for the Holosun HE512T, AR-height iron sights line up through the centre of the window rather than sitting in the lower third of it, so the reticle and the irons share the same point of aim.
Why choose an enclosed emitter on a rifle?
The emitter on the Holosun HE512T is sealed inside the Grade 5 titanium housing, so rain, mud and dust cannot settle in front of the LED. On an open reflex sight that is exactly what smears or blocks the dot in bad weather.
What reticle options does the Holosun HE512T have?
It uses the Multi-Reticle System, which switches between a 2 MOA red dot on its own, a 65 MOA circle on its own, and both together as a circle-dot. The 65 MOA circle is the fast close-range reference and the 2 MOA dot is the precise one.
Can I change the battery on the Holosun HE512T without losing zero?
Yes. The Holosun HE512T uses a side-loading CR2032 tray, so the cell can be replaced with the optic still mounted and zeroed.
Is the Holosun HE512T waterproof?
Yes. The Holosun HE512T is rated IPX8 in a Grade 5 titanium housing, so immersion in water is within its rating.
