Holosun K Mounting Plate for FN 509
Mix and match across the range: 2 items save 5%, 3 save 10%, 4 or more save 15% on your whole basket.
Not sure it fits your rifle? Ask us before you order
The Holosun KPLT-FN509 is a genuine Holosun adapter plate that carries a K footprint optic on FN 509 optics-ready slides using FN's MRD mounting system.
A plate is a small part with one job: make a slide cut in one pattern accept an optic machined in another. Get it wrong and nothing else on the pistol matters.
It is CNC machined from aircraft-grade aluminium with a hard-anodised finish, to Holosun's own tolerances rather than a third party's. The optic side is cut for the Holosun K footprint, the compact pattern Holosun uses on the 407K and 507K, and the slide side is shaped for the FN 509 MRD system.
This is the part to buy when a small K-series sight is going onto an FN 509 rather than a slide already milled for it. Two things worth knowing before you order: it will not take an RMR-footprint optic such as the 507C or 407C, and it will not take a 509T, which uses its own rear-lug pattern. Holosun does not state which screws are supplied with the plate, so plan on checking what arrives against the hardware already on your pistol.
It fits FN 509 models built around FN's MRD optic-mounting system, and takes K footprint optics. For a Glock MOS host the KPLT-MOS9MM is the right plate, for a CZ P-10 C the KPLT-CZP10C, and if your optic is a 509T rather than a K-series it needs the 509PLT-FN509T instead.
| Type | Optic adapter plate |
|---|---|
| Optic footprint | Holosun K (407K, 507K) |
| Host | FN 509 MRD optics-ready slides |
| Material | Aircraft-grade aluminium |
| Finish | Hard anodised |
| Machining | CNC machined |
| MPN | KPLT-FN509 |
Match the plate to the slide and the footprint to the plate, and the rest of the fitting is four screws. Order the KPLT-FN509 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: RMSc Footprint Red Dot Sights, KPLT-507C or browse all Holosun
| Brand | Holosun |
|---|---|
| Part no. | KPLT-FN509 |
| Category | Optic Mount |
| Barcode | 810047071112 |
£5 tracked UK delivery on every order via Royal Mail Tracked 24. Our products are ordered in from the manufacturer rather than held in UK stock, so please allow 7 to 10 business days (Monday to Friday, excluding bank holidays) from the date of your order for it to reach you. Tracking details are emailed on dispatch. UK delivery only.
You have 30 days from receiving your order to cancel it for any reason, then 14 days to send it back unused and in its original packaging. Faulty, damaged or incorrect items are replaced or refunded and we cover reasonable return postage. Refunds go back to your original payment method within 14 days of receiving the return.
7 to 10 business days from the date of your order. Every order is sent Royal Mail Tracked for a flat £5 and you receive tracking details by email when it is dispatched.
Yes. We list only genuine parts and optics from the brands shown, ordered in from the manufacturer for your order.
Compatibility notes on this page come from the manufacturer. If you are unsure, email us with your make and model before ordering and we will check rather than guess.
Yes. Bundle & Save applies automatically in your basket: 5% off when you buy 2 items, 10% off at 3 items and 15% off at 4 or more. It works across the whole range, so you can mix and match, and there is no code to enter.
Yes — you have 30 days from delivery to cancel for any reason, as long as the item is unused and in its original packaging. See our returns policy for the details.
Why Onyx Armaments
