The C&H Precision Weapons V4 Adapter for FN 509/510/545 with EPS Compatibility transforms your FN duty or carry pistol into a modern optics-ready platform. Built by a small family operation in Coastal Georgia, this precision-machined mounting plate gives you the ability to run a Holosun EPS or EPS Carry red dot on one of FN's most popular defensive and duty pistols. If you're already invested in an FN 509, 510, or 545 and want to add optics without replacing your gun, this adapter is the straightforward solution.

C&H machines every plate to tight tolerances on HAAS CNC equipment and runs each one through multiple quality checks before it ships. The 6061 aluminum construction gets a MIL-SPEC Type III hard anodized finish that stands up to carry and duty use. What sets this plate apart is the replaceable 416 stainless steel T-Post design—engineered to give you six to seven threads of engagement, which is well above industry standard. If any mounting hardware takes a hit in the field, you can replace just the hardware instead of scrapping the whole plate.

Installation is straightforward: the package includes everything you need to mount it to your slide and attach your optic. Whether you're setting up a duty gun, a home-defense platform, or a carry pistol that works harder when you can see what you're aiming at, this adapter handles the job without any guesswork or compatibility surprises.

Key Features

• Precision-machined 6061 aluminum construction with MIL-SPEC Type III hard anodized finish
• Patented stainless steel T-Post design with industry-leading thread engagement (6–7 threads)
• Replaceable mounting hardware—swap screws and T-nuts without replacing the plate
• Converts FN 509, 510, and 545 slides for Holosun EPS and EPS Carry red dots
• Complete mounting package included; no adapter hunting required

Specifications

Compatibility	FN 509, 510, 545 (Holosun EPS/EPS Carry)
Material	6061 Aluminum
Finish	MIL-SPEC Type III Hard Anodized
Fastener Material	416 Stainless Steel T-Posts
Included Hardware	(1) Optic Plate, (2) M3 Plate Mounting Screws, (2) 4-40 Mounting Screws, (2) 416 SS T-Nuts

Frequently Asked Questions

Will this adapter work with my FN 509, 510, or 545?

Yes. The C&H Precision V4 Adapter is specifically designed to convert these three FN slide platforms for use with Holosun EPS and EPS Carry optics.

What's included in the box?

You get one optic plate, two M3 plate mounting screws, two 4-40 mounting screws, and two 416 stainless steel T-nuts—everything needed to mount the adapter to your slide and secure your optic.

If I damage a screw or T-nut, do I have to replace the entire plate?

No. All mounting hardware is replaceable. You can order replacement screws and T-nuts individually, so a minor impact doesn't mean buying a new adapter.

What makes the T-Post design better than standard mounts?

The 416 stainless steel T-Posts are engineered to deliver six to seven threads of engagement—above the industry standard. This design gives you a more secure hold and reduces the risk of the optic shifting under recoil.