Arisaka Defense Offset Plate, Holosun 407K & 507K For 1.9''- 2.2'' Scope Mount

The Arisaka Defense Offset Plate for Holosun 407K & 507K red dots designed for 1.9"–2.2" scope mounts gives you a modular way to mount a compact red dot sight alongside larger optics without the guesswork. This tall-height plate slots into Arisaka's patent-pending offset mounting system, letting you run your Holosun on an AR-15 Picatinny rail while keeping a primary scope in place. It's the kind of setup hunters and tactical shooters use when they want speed at close range but keep their magnified glass ready for distance.

The system works through reversible base and plate design—pick your offset angle (35 or 45 degrees), mount the plate to the base, and you're dialed. The 45-degree position gives extra breathing room around larger turrets and higher-power scopes, which matters if you're running a chunky variable optic or a bigger objective bell. When you tilt your rifle to use the offset red dot, the sight stays centered over bore and holds a lower 1/3 co-witness height, so your point of aim doesn't drift. The plate itself is cut from 6061-T6 aluminum and hard anodized to MIL spec, so it handles recoil and field use without flex or creep.

What makes Arisaka's approach smart is the modular path: buy just the plate now, upgrade the base later, or swap plates as you acquire new optics. The mounting footprint takes three Picatinny slots with twin recoil lugs and a clamping screw, and sits 0.180" above the rail. Torx Plus bit drivers come included. If you're building an AR with a scope and want a lightweight, rigid co-witness red dot option, this plate solves the geometry problem without compromise.

Key Features

• Modular plate design fits Holosun 407K and 507K to larger scope mounts (1.9"–2.2" height)
• 35 or 45-degree offset positions to clear turrets and larger optic bodies
• Reversible for left or right-side rail mounting
• 6061-T6 aluminum, MIL-A-8625 Type III hard anodized for durability
• Maintains lower 1/3 co-witness and bore-center aim point
• Three-slot Picatinny footprint with twin recoil lugs
• Torx Plus bit drivers included

Specifications

Frequently Asked Questions

Will this plate work with my Holosun 407K or 507K?

Yes. This is the tall-height plate designed specifically for Holosun 407K and 507K mounting when your scope tube diameter is between 1.9" and 2.2". The 407K and 507K sit on this plate within the Arisaka system.

Can I use this on the left side of my AR's receiver?

Yes. The base and plates are reversible, so you can mount the assembly on either the left or right side of your Picatinny rail.

What's the difference between the 35 and 45-degree offset positions?

The 35-degree position brings the red dot closer to smaller, slimmer scopes. The 45-degree position provides more clearance around larger turrets and wider optic bodies, like high-magnification variables. Your Arisaka base supports both angles; you choose which suits your scope.

What comes with the plate, and what do I need to buy separately?

This plate comes with Torx Plus bit drivers. You'll need an Arisaka Defense offset base (sold separately) to complete the mounting system. The base and plate work together; neither functions alone.