Description
This precision-machined adapter bridges your Holosun 509T enclosed reflex sight to any RMR/HS507C footprint pistol slide.
Mount your Holosun 509T optic on a wider range of firearms with this dedicated adapter plate. Designed for shooters who want the durability and protection of an enclosed reflex sight on handguns cut for the popular RMR/HS507C mounting pattern, this adapter provides a secure connection between your 509T and your slide. The low-profile design maintains a clean sight picture while chamfered edges ensure compatibility with most optics-ready holsters for everyday carry.
Key Features
- Universal RMR/507C Compatibility: Fits any pistol slide machined for Trijicon RMR or Holosun HS507C footprint, including Glock MOS, Walther PDP, Springfield XD-M Elite, and CZ P-10 series
- Secure Mounting Platform: Low-profile design with chamfered edges provides stable optic mounting while maintaining compatibility with most optics-ready holsters
- Corrosion-Resistant Finish: Hard-coat anodized black finish protects against environmental wear and matches most firearm finishes
Important Compatibility Notes
This adapter is designed specifically for the Holosun 509T model. Please note:
- NOT compatible with Holosun 509 ACSS Vulcan models (different footprint—the 509T and 509 ACSS have distinct mounting patterns)
- NOT compatible with ZEV or Brownells slides that use threaded boss-style RMR interfaces (requires different mounting screws)
- Requires pistol slide already cut for RMR or HS507C footprint
- If your slide requires an adapter plate to convert to RMR footprint, you may need to stack two plates (one to convert slide to RMR, then this plate for the 509T)
Why We Carry It
The Holosun 509T represents a significant advancement in pistol red dot technology with its fully enclosed emitter design, protecting the LED from debris, impacts, and the elements. However, since most optics-ready pistols come cut for the RMR or HS507C footprint rather than the 509T’s proprietary rail-style mount, this adapter solves a critical compatibility gap. Holosun includes this adapter with new 509T purchases, but replacement plates are essential for shooters running multiple pistols or replacing lost hardware. The 509T’s enclosed design, combined with this adapter’s low profile, keeps your setup streamlined without sacrificing the durability advantages that make enclosed emitters increasingly popular among serious shooters.
Frequently Asked Questions
Will this adapter work with my Holosun 509 ACSS Vulcan optic?
No. The 509T and 509 ACSS Vulcan have different footprints despite their similar appearance. The 509 ACSS Vulcan is slightly longer to accommodate its larger emitter and ACSS reticle. If you have a 509 ACSS, you’ll need the version that comes with an RMR adapter plate already matched to that specific model.
Do I need to purchase mounting screws separately?
No. This adapter includes all necessary mounting hardware. However, some aftermarket slides with specific configurations (particularly those with threaded bosses or modified depths) may require different length screws. The standard screws work for most factory optics-ready slides and slides cut to standard RMR specifications.
Will my current suppressor-height sights still be visible with this adapter?
This depends on your specific sight height and the adapter’s added height. The adapter adds approximately 5mm of deck height. Some shooters report losing lower 1/3 co-witness when stacking this adapter on certain pistol models, particularly if your slide already requires another adapter to convert to RMR footprint. For absolute co-witness or lower 1/3, you may need taller suppressor-height sights.
Spec Sheet
- Model Number: 509PLT-507C
- UPC: 810047071051
- Color: Black
- Finish: Hard-coat anodized
- Length: 45mm
- Mounting Height (BH): 5mm
- Compatible Optic: Holosun 509T (NOT 509 ACSS Vulcan)
- Compatible Slide Cut: RMR / HS507C footprint
