The Reptilia DOT Mount is a one-piece Picatinny optic mount for the Holosun 509T, placing the optical axis 1.93in (49 mm) above the rail.
The 509T has its own footprint and will not sit on an RMR mount. This is the one cut for it, at the tall height.
Machined from billet 7075-T6 aluminum in a Milspec Type III hard anodized finish, the mount attaches to any M1913 Picatinny rail and holds the 509T on a dedicated interface rather than through an adapter. A nitrided 4140 steel clamp closes onto the rail, and the assembly weighs 2.0 oz (57 g).
The 509T is an enclosed-emitter dot, which is the reason a lot of shooters pick it — the LED is sealed inside the housing, so rain and mud cannot bridge the gap and dim it. Putting it on a mount machined for its own footprint keeps the joint count down to one. Made in the USA.
Key Features
- 509T footprint: Cut for the Holosun 509T's own pattern, not an RMR mount with a plate on top
- Optical axis at 1.93in (49 mm): Head-up shooting position with clearance for a helmet or night vision
- 2.0 oz (57 g): Billet 7075-T6 aluminum, Milspec Type III hard anodized
- Nitrided 4140 steel clamp: Sits flush with the mount body for an anti-snag profile
- Enclosed-emitter friendly: One fixed interface under a sealed optic, with nothing extra in the stack
Compatibility & Fitment
Fits the Holosun 509T, including the HE509T variants, on any M1913 Picatinny rail — including the flat-top upper of an AR-15. Footprint and height are both fixed: 509T footprint at a 1.93in optical axis. Standard AR-15 back-up iron sights do not co-witness at this height. A Holosun 507 or 508 uses the Trijicon RMR footprint and needs the RMR/SRO DOT Mount, not this one.
Technical Specifications
Platform | AR-15 / M4 |
Fits | Holosun 509T, on any M1913 Picatinny rail |
Type | One-piece red dot mount — 1.93in (49 mm) optical axis over rail |
Material | Billet 7075-T6 aluminum; nitrided 4140 steel clamp |
Finish | Milspec Type III hard anodized — Black, Flat Dark Earth Anodized |
Weight | 2.0 oz (57 g) |
Mount interface | Spring-loaded clamp to M1913 Picatinny |
Made in | USA |
Brand | Reptilia |
US Shipping & Support
Shipped from D&R Sports Center in the USA with fast, tracked delivery. Questions on fit, mounting or which model suits your setup? Our team is glad to help before and after your purchase.
Frequently Asked Questions
Why will a 509T not fit an RMR mount?
Because Holosun gave the 509T an enclosed housing with its own mounting pattern rather than the open-emitter RMR geometry the 507 and 508 use. The screw positions and the recoil surfaces are in different places. There is no shim or plate that makes an RMR mount hold a 509T properly, which is why Reptilia machines a separate mount for it.
Does it fit the HE509T-RD and similar variants?
Reptilia lists the 509T against this mount, and the HE509T variants share the same housing and mounting pattern. If you are running a Primary Arms-branded version of the same optic, check the base against Holosun's own 509T specification before ordering — the reticle differs, the footprint should not.
Is 1.93in the only height?
For the 509T in Reptilia's DOT range, yes — this listing is the 1.93in version and Reptilia does not publish a lower-third 509T DOT Mount. If you need a 509T low over a shotgun receiver instead of on a rail, Reptilia's SADDLE for the Beretta 1301 and A300 is a different product built for exactly that.
Will my back-up sights co-witness?
No. At 1.93in standard AR-15 back-up iron sights sit below the optic window rather than inside it. Treat them as a separate sighting system at this height, or choose a lower mount if seeing both at once matters to you.
