The Holosun 509PLT-507C is an adapter plate that lets a Holosun 509 series enclosed optic sit on a slide already cut for the 507C or Trijicon RMR footprint.
The 509T uses a rear-lug footprint of Holosun's own, so it will not bolt onto an RMR cut. This plate is the piece that bridges the two patterns.
It is machined by Holosun from aluminium and hard-anodised, to the same tolerances as the optics it carries, which is the argument for a factory plate over a generic one: the lug pockets and screw positions are cut by the company that cut the optic. Holosun publish no weight or dimensions for the plate, and list no hardware content on the product page, so check what your slide and optic already have before fitting.
The practical gain is that an enclosed 509 series sight can go onto a host whose slide was machined years ago for an open-emitter RMR-pattern optic, without recutting anything. That matters because a sealed emitter cannot be blanked by rain, grit or propellant residue the way an exposed LED can. The limitation is narrow and worth stating: this plate is for 509 series optics on 507C and RMR cuts only. It will not carry an RMR-footprint sight such as the 507C or 407C, and it will not carry an RMSc-footprint sight such as the 507K or 407K.
Why shooters choose the 509PLT-507C
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Optic side — Holosun 509 series enclosed optics, on the 509T rear-lug footprint
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Slide side — pistol slides cut for the 507C or Trijicon RMR footprint
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Material — aluminium, hard-anodised
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Not compatible — RMR-footprint optics such as the 507C, or RMSc optics such as the 507K
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Source — a genuine Holosun part rather than a generic adapter
What the 509PLT-507C fits
The host has to be a 507C or RMR cut, and the optic has to be a 509 series sight. Other hosts have their own plate: the 509PLT-MOS9MM is the Glock MOS version and the 509PLT-CZP10 the CZ P-10 version. If the optic has to go on a rail rather than a slide, use the 509T Picatinny mount at 0.82in.
Specifications
| Type |
Optic adapter plate |
| Optic footprint |
Holosun 509T rear-lug (509 series enclosed optics) |
| Host slide cut |
507C / Trijicon RMR footprint |
| Material |
Aluminium |
| Finish |
Hard-anodised |
| MPN |
509PLT-507C |
A small machined part, but the only thing standing between a 509 series sight and an RMR-cut slide. Order the 509PLT-507C today — imported from the USA with all duties paid by us and dispatched tracked from the UK in 7–10 business days, with nothing to pay on delivery.
Explore more: Optic Mounts, 509T Picatinny Mount 1.63in or browse all Holosun.
