Arisaka Defense Offset Mount Base - Precision Picatinny Aluminum, Tactical Black Finish

The Arisaka Defense Offset Mount Base is a modular Picatinny mounting solution designed for AR15 rifles that need a red dot sight positioned off to the side of a primary scope. Unlike fixed offset mounts, this base lets you choose between 35-degree and 45-degree angles without buying different hardware—the shallower 35-degree works best when you're running a slim, compact scope, while the 45-degree gives you more breathing room around larger turrets or high-magnification glass. Because the mount pivots on the top rail and the optic stays centered over the bore when you cant the rifle, you maintain a reliable lower-1/3 co-witness sight picture every time.

Built from 6061-T6 aluminum with MIL-A-8625 Type III hard-coat anodizing in tactical black, this is a shooter's mount—rugged enough for duty use, precise enough for precision rifle work. It occupies three Picatinny slots and weighs just 1.9 ounces without an optic. The base and optic plates are reversible, so you can mount on either the left or right side of the rail. Torx Plus bit drivers are included, and both base and plates can be purchased separately as your optic collection grows.

Arisaka's modular system supports an extensive lineup of red dots across two height categories—standard (1.5" to 1.8" scope mounts) and tall (1.9" to 2.2" scope mounts)—so compatibility with your specific optic is straightforward. Whether you're building a DMR-style rifle, a close-quarters AR, or a hunting platform, the offset mount base gives you flexible, field-proven performance without compromise.

Key Features

• 35- and 45-degree offset angles—select the position that best clears your primary scope
• Reversible base and plates for left- or right-side rail mounting
• Maintains lower-1/3 co-witness height and bore-centerline alignment when canted
• CNC-machined 6061-T6 aluminum with hard-coat anodize—durable tactical finish
• Modular design: base and optic plates sold separately for future upgrades
• Includes Torx Plus bit drivers for field maintenance
• Compact footprint: 1.0" length, 0.180" height above rail

Specifications

Frequently Asked Questions

What red dot sights does the Arisaka offset mount support?

The base accommodates two height categories. Standard height (1.5" to 1.8" scope mounts) supports Docter, Eotech MRDS, Insight, Meopta, Vortex Venom/Viper, Burris Fastfire III, Trijicon RMR/SRO, Holosun 407C/507C/508T, Swampfox Kingslayer/Sentinel, Liberty, Justice, SIG Romeo Zero, Leupold Delta Point Pro, JPoint, Shield RMS/RMSc, Aimpoint Micro T1/T2/H1/H2, SIG Romeo 4/5, Holosun HS403/HS503/HS515/HS530, and Aimpoint Acro. Tall height (1.9" to 2.2" scope mounts) includes most of these in different plates. Check the product specs for your specific optic's plate number.

Can I use this mount on either side of my AR15?

Yes. The base and optic plates are reversible, allowing you to mount the offset sight on the left or right side of the top Picatinny rail depending on your needs and shooting position.

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

The 35-degree offset positions the red dot closer to the centerline, making it ideal for use with slimmer, smaller-diameter primary scopes. The 45-degree offset provides additional clearance around larger turrets and high-magnification scopes. You can select the angle that best suits your optic configuration.

Do I need to buy separate optic plates, or does the base include them?

The mount base is sold separately from the optic plates. You select and purchase the plate that matches your red dot sight and scope mount height. This modular design allows you to upgrade or add new optics in the future by purchasing only the plate you need.