The Holosun 509 (model HE509T) is a Chinese-made enclosed emitter optics developed by Holosun Technologies. Designed for use on a gun, it stands out for its Grade 5 titanium housing, Solar Failsafe technology and multiple crosshair, making it one of the most robust compact optics on the market in its price range.
History and Development of the Holosun 509
Holosun Technologies, founded in 2013 in California with production based in China, has quickly established itself as a major player in the compact tactical optics market. The 509 series was launched to meet the growing demand for “enclosed emitter” optics — that is, where the LED emitter is fully protected by a rigid cover, unlike conventional open reflex designs. This architecture protects the transmitter from debris, water, and shock, greatly improving reliability in harsh conditions.
The HE509T differs from previous models by its Grade 5 titanium case (the same alloy used in aeronautics), which is much lighter and stronger than 7075 aluminum. The X2 version, launched in 2022, brings several improvements over the original, including improved multi-coated glass and expanded compatibility with RMR turntables. Holosun also offers red and green versions to suit shooters’ preferences.
Technical Specifications
| Feature | Specification |
|---|---|
| Official designation | Holosun HE509T-RD X2 / HE509T-GR X2 |
| Country of Origin | China (Holosun Technologies) |
| Lens Type: | Enclosed Emitter Reflex Sight (Closed Red Dot) |
| Reticle | 2 MOA dot / 32 MOA circle / circle+dot (Multiple Reticle System) |
| Grade 5 titanium | case |
| Dimensions | 40.6 × 29.5 × 28.7 mm |
| Visible window | 16.8 × 22.9 mm |
| Weight | 48.8 g |
| Power supply | CR1632 battery (included) + Solar Failsafe |
| Battery life | 50,000 hours (single point, setting 6) |
| Brightness settings | 10 daytime + 2 night vision levels |
| water resistance | (submersion up to 1 m) |
| Compatibility | Platinum RMR / Holosun 509 footprint |
| Shake Awake, Solar Failsafe, Last Setting Recall | Technology |
Operation and Technical Particularities
The Holosun 509 uses a Super LED powered simultaneously by a CR1632 battery and a solar panel integrated at the top of the case (Solar Failsafe). In conditions of sufficient ambient light, the solar panel takes over from the battery, significantly extending the range. Shake Awake technology puts the optics to sleep after a period of inactivity and reactivates it as soon as motion is detected, preserving battery life without sacrificing responsiveness.
The Multiple Reticle System (MRS) allows switching between three reticle configurations — 2 MOA point alone, 32 MOA circle alone, or circle+dot combination — without the need for re-zeroing. Enclosed design protects the transmitter from gas splashes, gunshot debris, and rain. The Grade 5 titanium case offers a higher strength-to-weight ratio than traditional aluminum, while also being more resistant to corrosion.
Variants and Versions
The 509 range includes several versions: the HE509T-RD X2 with red dot, the HE509T-GR X2 with green dot (less tiring for the eye in prolonged use), and versions with ACSS Vulcan reticle developed in partnership with Primary Arms. There is also the “standard” 509T model with aluminum housing at a more affordable price. The 509K is an even more compact version for pocket weapons with a reduced firing window.
Use and Compatibility
The Holosun 509 is compatible with all frames to the RMR (Trijicon RMR Footprint) standard, which has become the dominant industry standard for modern pistols. It natively fits Glock MOS, SIG Sauer P320/P365 with adapted turntable, Smith & Wesson M&P, CZ P-10, and many other modern semi-automatic pistols machined to accommodate an optics. Several manufacturers now offer turntables directly adapted to the 509 footprint.
Civil Possession in Switzerland
In Switzerland, the Holosun 509 is an optical accessory and not a firearm. Its acquisition is free for any adult Swiss resident, without the need for a weapons acquisition permit. It can be mounted on a legally owned semi-automatic pistol. In accordance with the Federal Weapons Act (Arms Act), however, the acquisition of the carrier weapon requires an acquisition permit issued by the competent cantonal authority. The conditions include: being at least 18 years old, not being under general guardianship, and not presenting a reason for refusal within the meaning of Art. 8 (2) Arms Act.
Conclusion
The Holosun 509 (HE509T) represents one of the best value for money in the segment of enclosed emitter optics for pistols. Its titanium case, Solar Failsafe technology and multiple crosshair system make it a reference choice for sport shooters, IPSC/USPSA practitioners and professionals looking for a robust optic without compromise. He helped democratize high-quality optics in the service and competition pistol market.
