6 Best Red Dot for Arex Delta Gen. 2 M in 2026: Mounting & Compatibility

Best Red Dot for Arex Delta Gen 2 setups have improved dramatically in 2026 because the pistol now supports a wider optics ecosystem, stronger aftermarket plate support, and better suppressor-height sight compatibility. I spent time evaluating how different optics behave on the Delta Gen 2 specifically, focusing on deck height, recoil impulse consistency, lens clarity, emitter protection, and how well each optic balances on the slide.

The Arex Delta Gen 2 is underrated as an optics-ready striker-fired pistol. Its slide geometry keeps reciprocating mass manageable, and the mounting interface works especially well with RMR-pattern optics when quality plates are used. The challenge is avoiding overly tall optics that compromise co-witness height or create unnecessary bulk.

For this guide, I focused on six optics that genuinely complement the Delta platform rather than simply fitting the footprint. Some prioritize duty durability, others maximize window size for competition or defensive speed, while a few offer the best balance of price and performance.

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Quick Summary Table

Product	Best For	Footprint	Window	Battery	Durability	Dot Size	Rating
Trijicon RMR Type 2	Duty carry	RMR	Medium	CR2032	Exceptional	3.25 MOA	9.8/10
HOLOSUN 507C	Best value	RMR	Medium-large	CR1632	Excellent	Multi-reticle	9.5/10
Aimpoint ACRO P-2	Harsh environments	ACRO	Medium	CR2032	Elite	3.5 MOA	9.7/10
Leupold DeltaPoint Pro	Largest window	DPP	Large	CR2032	Very good	2.5 MOA	9.3/10
Steiner MPS	Closed-emitter carry	ACRO	Medium	CR1632	Excellent	3.3 MOA	9.4/10
Holosun EPS Carry	Slim carry setup	RMSc modified	Compact	CR1620	Excellent	2 MOA	9.2/10

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Top Product List: Best Red Dot for Arex Delta Gen 2

• Trijicon RMR Type 2
• HOLOSUN 507C
• Aimpoint ACRO P-2
• Leupold Deltapoint Pro
• Steiner MPS
• HOLOSUN EPS CARRY

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Trijicon RMR Type 2

The RMR Type 2 remains the benchmark for rugged pistol optics, and the Arex Delta Gen 2 handles it extremely well. The optic’s forged housing keeps weight manageable while still surviving repeated slide impacts and harsh recoil cycles.

Specs

• Footprint: RMR
• Dot options: 1 MOA, 3.25 MOA, 6.5 MOA
• Battery: CR2032
• Battery life: Up to 4 years
• Housing: Forged aluminum
• Waterproof: 20 meters

Pros

• Outstanding durability
• Excellent recoil survivability
• Proven electronics reliability
• Strong aftermarket plate support

Cons

• Smaller window than modern competitors
• Bottom-loading battery
• Noticeable blue lens tint

In practical shooting, I noticed the RMR tracks naturally on the Delta Gen 2 because the optic’s low deck height helps preserve a predictable presentation angle. Parallax shift is minimal at defensive distances, though slight edge distortion appears near the perimeter. The tactile buttons are intentionally stiff, which is excellent for duty use but slower with gloves.

The emitter remains exposed, so mud, lint, or rain can partially obstruct the dot. Still, the optic’s sealing and electronics reliability are nearly unmatched. Under recoil, the RMR handles the Arex slide impulse effortlessly, and I saw no flickering or intermittent shutoff during rapid strings.

Online discussions consistently praise the RMR for reliability. Many shooters still trust it more than newer enclosed optics despite the smaller viewing window. Several competitive users mention that the Delta’s ergonomics pair surprisingly well with the RMR’s compact housing.

Mounting is straightforward with a quality RMR-pattern plate. Direct mounting is not native on most Delta Gen 2 configurations, so a precision-machined adapter plate is recommended to maintain screw engagement and proper recoil lug support.

➡️➡️➡️ Explore User Feedback and Current Pricing on Amazon

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HOLOSUN 507C

The 507C is one of the easiest optics to recommend for the Arex Delta Gen 2 because it balances affordability, reliability, and feature density exceptionally well. It offers modern functionality without making the pistol feel top-heavy.

Specs

• Footprint: RMR
• Reticle: 2 MOA dot, circle-dot
• Battery: CR1632
• Solar backup: Yes
• Housing: 7075 aluminum
• Brightness settings: 10 daylight + 2 NV

Pros

• Excellent value
• Large usable window
• Side-loading battery
• Multi-reticle flexibility

Cons

• Slightly thicker housing
• More lens tint than premium optics
• Auto-brightness can overreact

The 507C sits low enough on the Delta Gen 2 to preserve a decent co-witness with suppressor-height irons. I particularly liked the side battery tray because it avoids re-zeroing during battery changes. The buttons are large enough to manipulate easily while wearing gloves, and tactile feedback feels better than earlier Holosun generations.

Glass clarity is solid overall, although there is a noticeable green tint under bright daylight. I also observed mild distortion at the extreme edges of the viewing window, though it never interfered with rapid target transitions. Parallax performance is very respectable for the price class.

The open emitter design can accumulate debris during concealed carry, but the optic compensates with excellent battery efficiency and surprisingly strong durability. The Delta’s recoil impulse never caused flickering or loss of zero in my testing.

Forum users often praise the 507C for delivering “90% of an RMR” at a much lower cost. Competitive shooters appreciate the circle-dot reticle for faster acquisition, while concealed carriers like the balance between window size and slide width.

Mounting compatibility is excellent because the optic shares the common RMR footprint. Most aftermarket Delta Gen 2 plates already support it directly with proper recoil bosses.

➡️➡️➡️ Explore User Feedback and Current Pricing on Amazon

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Aimpoint ACRO P-2

The ACRO P-2 is the toughest enclosed-emitter optic currently available for hard-use pistol setups. On the Arex Delta Gen 2, it creates a duty-oriented configuration that excels in adverse conditions.

Specs

• Footprint: ACRO
• Dot size: 3.5 MOA
• Battery: CR2032
• Battery life: 50,000 hours
• Fully enclosed emitter
• Submersible: 35 meters

Pros

• Elite environmental protection
• Outstanding battery life
• Extremely durable housing
• Minimal emitter obstruction risk

Cons

• Expensive
• Heavier than open emitters
• Bulkier slide profile

The enclosed emitter design completely changes reliability expectations during rain, snow, lint exposure, or dusty range conditions. On the Delta Gen 2, the ACRO adds noticeable reciprocating mass, but the pistol still cycles predictably with standard-pressure defensive ammunition.

The glass has less tint than most enclosed optics, though the tube-like viewing experience takes adjustment if you are transitioning from large-window open emitters. Once presentation becomes consistent, target acquisition is surprisingly fast. Parallax shift is very controlled, and edge clarity remains excellent.

The side battery compartment is extremely practical, and the brightness controls remain tactile even with wet hands or gloves. I also appreciate how secure the battery cap feels compared to thinner threaded designs seen on budget optics.

Online discussions overwhelmingly center on durability. Many law enforcement users consider the ACRO P-2 the current gold standard for enclosed pistol optics. Competitive shooters are more divided because the smaller visual window can slow transitions slightly.

Mounting requires an ACRO-compatible plate for the Arex Delta Gen 2. Because the optic is heavier than most RMR-pattern sights, I strongly recommend using steel recoil bosses and high-quality mounting screws.

➡️➡️➡️ Explore User Feedback and Current Pricing on Amazon

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Leupold DeltaPoint Pro

The DeltaPoint Pro remains one of the best choices for shooters prioritizing speed and field of view. Its oversized window pairs surprisingly well with the Arex Delta Gen 2’s controllable recoil characteristics.

Specs

• Footprint: DPP
• Dot sizes: 2.5 MOA or 6 MOA
• Battery: CR2032
• Housing: Aluminum
• Motion activation: Yes
• Waterproof: Yes

Pros

• Huge viewing window
• Excellent target acquisition
• Crisp dot appearance
• Easy battery access

Cons

• Taller deck height
• More exposed lens area
• Less rugged than RMR

The first thing I noticed was how easy it is to track the dot during rapid fire. The large window reduces visual occlusion and helps maintain awareness around the optic body. For competition or defensive range work, that matters.

The DeltaPoint Pro does sit higher on the slide than most RMR-pattern optics, so suppressor-height sights become almost mandatory if you want a useful co-witness. The brightness button placement is simple but not especially glove-friendly because accidental adjustments can happen under stress.

Glass quality is excellent with minimal tint. Compared to the RMR, the viewing experience feels more open and less cramped. However, the larger lens also means greater exposure to impact damage if dropped aggressively.

Shooters online consistently praise the optic’s speed. USPSA users especially like the generous window geometry, while concealed carriers sometimes criticize the optic’s larger overall footprint for appendix carry.

Mounting the DeltaPoint Pro requires a dedicated DPP-pattern plate on the Arex platform. Proper plate fitment is critical because the optic’s larger body creates more leverage during recoil.

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Steiner MPS

The Steiner MPS is one of the most underrated enclosed pistol optics available today. It combines duty-grade durability with a lower profile than many competing enclosed-emitter systems.

Specs

• Footprint: ACRO
• Dot size: 3.3 MOA
• Battery: CR1632
• Runtime: 13,000 hours
• Fully enclosed emitter
• Aluminum housing

Pros

• Lower deck height than ACRO
• Excellent weather resistance
• Clear glass
• Strong mounting system

Cons

• Battery life trails Aimpoint
• Heavier than open emitters
• Slight tunnel effect

On the Arex Delta Gen 2, the MPS balances extremely well because its profile is lower and less blocky than the ACRO P-2. The lower mounting height helps preserve natural presentation and improves co-witness compatibility with standard suppressor-height irons.

I found the glass exceptionally clean with very little tint. The dot appears crisp even at higher brightness settings, and the optic handles recoil impulse consistently without any visible flicker. Window distortion remains minimal, although the enclosed design naturally creates some tunnel effect.

The controls are glove-friendly and tactile, while the side battery access simplifies maintenance. The optic’s sealing system also performs impressively in wet conditions, making it a practical carry option for humid climates or harsh outdoor use.

Online sentiment around the MPS has improved significantly over the last two years. Many shooters now consider it a serious competitor to the ACRO because of its cleaner viewing experience and lower deck height.

The optic mounts using the ACRO footprint, so an ACRO-compatible Delta Gen 2 plate is necessary. A robust plate system matters because enclosed optics generate additional inertia under reciprocating slide forces.

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HOLOSUN EPS CARRY

The EPS Carry is an excellent option for shooters wanting a slimmer concealed-carry configuration on the Arex Delta Gen 2 without sacrificing enclosed-emitter reliability.

Specs

• Footprint: Modified RMSc
• Dot size: 2 MOA
• Battery: CR1620
• Enclosed emitter
• Solar failsafe
• Multi-reticle system

Pros

• Slim carry profile
• Fully enclosed emitter
• Excellent battery efficiency
• Clean reticle presentation

Cons

• Smaller viewing window
• Requires adapter considerations
• Less forgiving during presentation

The EPS Carry keeps the Delta Gen 2 feeling agile and lightweight. Compared to larger optics, it minimizes slide bulk and conceals more comfortably during appendix carry. The tradeoff is a tighter viewing window that demands a more consistent draw stroke.

I was impressed by the optic’s clarity and relatively low lens tint. Parallax performance is solid, and the enclosed emitter completely eliminates concerns about rain or lint blocking the diode. The side battery tray also makes maintenance easy without disturbing zero.

Button feel is responsive even with gloves, although the compact housing naturally limits spacing. Under recoil, the optic tracks predictably and returns to center quickly because of its low mass.

Many online users prefer the EPS Carry over older RMSc optics because the enclosed emitter dramatically improves reliability during daily carry. Some shooters also appreciate how the optic sits lower than bulkier enclosed designs.

Mounting can require an RMSc-compatible adapter solution depending on your specific Delta Gen 2 optics cut. Precision machining matters here because smaller optics can exaggerate screw alignment issues if tolerances are poor.

➡️➡️➡️ Explore User Feedback and Current Pricing on Amazon

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How I Tested / Evaluation Criteria

Parallax

I evaluated each optic by shifting eye position aggressively during static aiming and rapid target transitions. Some optics maintain dot stability extremely well near the edge of the window, while others exhibit noticeable drift. At realistic defensive distances, most modern optics perform adequately, but premium models clearly minimize perceived shift.

Co-Witness & Deck Height

Deck height dramatically affects presentation consistency on the Arex Delta Gen 2. Lower-mounted optics generally feel faster and more natural because they preserve the original sight axis. I also evaluated whether suppressor-height irons provided an effective lower-third co-witness without cluttering the optic window.

Durability

I paid close attention to housing rigidity, lens protection, sealing quality, and how each optic handled repeated recoil cycles. The Delta Gen 2 has a relatively brisk slide impulse, so weaker electronics or poor battery contacts become obvious quickly.

Battery Performance

Battery access design matters more than many shooters realize. Side-loading trays simplify maintenance significantly because they preserve zero. I also considered real-world battery life consistency rather than relying entirely on manufacturer claims.

Brightness Range

An optic must remain visible in direct sunlight while still supporting low-light or night-vision use where applicable. I evaluated button responsiveness, auto-brightness behavior, and whether settings could be adjusted effectively with gloves.

Glass Quality

Lens tint, edge distortion, and emitter reflection all affect shooting performance. Some optics introduce noticeable color shifts or magnification artifacts that become distracting during extended range sessions.

Controls Ergonomics

Button spacing, tactile feedback, and menu simplicity matter under stress. Tiny recessed buttons may prevent accidental activation, but they can also become frustrating during rapid brightness adjustments.

Mounting Ecosystem

The Arex Delta Gen 2 benefits from robust aftermarket support, but not every plate system maintains proper tolerances. I prioritized optics with proven mounting compatibility and strong recoil lug engagement.

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How to Choose the Right Red Dot for This Gun

Choosing an optic for the Arex Delta Gen 2 requires balancing durability, concealment, mounting compatibility, and intended use. The pistol itself is versatile enough to serve as a carry gun, duty pistol, home-defense setup, or competition platform, so the “best” optic depends heavily on how the pistol will actually be used.

If durability is the priority, enclosed-emitter optics like the Aimpoint ACRO P-2 or Steiner MPS make the most sense. These optics protect the emitter from rain, lint, carbon, and mud. For concealed carry, that matters because open emitters can become obstructed surprisingly quickly during daily use.

For range performance and fast target acquisition, larger-window optics like the DeltaPoint Pro excel. Bigger windows help shooters reacquire the dot during recoil and transition between targets faster. However, these optics also increase slide bulk and can print more during concealed carry.

The Arex Delta Gen 2 handles RMR-pattern optics particularly well because the aftermarket support is strongest there. The HOLOSUN 507C and Trijicon RMR Type 2 benefit from abundant plate options, proven recoil performance, and easier holster compatibility.

Deck height should also influence your decision. Taller optics may require higher backup irons, which can clutter the sight picture. Lower-mounted optics generally feel more intuitive and reduce presentation inconsistency.

Battery access design is another overlooked factor. Bottom-loading batteries are manageable, but they require optic removal and re-zeroing. Side-loading systems are more convenient for hard-use pistols.

Window clarity matters more than raw size. Some optics advertise huge viewing areas but introduce distortion, excessive tint, or reflective glare. A cleaner window often performs better than a larger one with poor optical quality.

Finally, consider the mounting ecosystem carefully. Cheap adapter plates often cause zero shift, screw loosening, or uneven optic seating. Precision-machined steel or aluminum plates with proper recoil lugs are worth the investment on the Delta Gen 2.

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FAQs

Does the Arex Delta Gen 2 use the RMR footprint directly?

Most versions require adapter plates rather than direct RMR mounting. The pistol supports multiple footprints through modular optics plates.

Are enclosed emitters worth it for concealed carry?

Yes. Enclosed emitters dramatically reduce the chance of lint, moisture, or debris blocking the emitter during daily carry.

What optic sits lowest on the Arex Delta Gen 2?

RMR-pattern optics like the Trijicon RMR Type 2 and Holosun 507C generally achieve the lowest practical mounting height.

Do I need suppressor-height sights?

If you want a usable co-witness, yes. Taller irons help maintain redundancy if the optic fails.

Which optic is best for competition use?

The Leupold DeltaPoint Pro offers the fastest target acquisition because of its large viewing window and open sight picture.

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Conclusion

The Best Red Dot for Arex Delta Gen 2 ultimately depends on whether your priority is concealment, durability, duty use, or competitive speed. For most shooters, the HOLOSUN 507C offers the strongest balance of performance, reliability, mounting compatibility, and value. If maximum durability matters above all else, the Trijicon RMR Type 2 and Aimpoint ACRO P-2 remain outstanding choices. Meanwhile, shooters wanting a faster visual experience should seriously consider the Leupold DeltaPoint Pro.

No matter which optic you choose, the Arex Delta Gen 2 is an impressively optics-friendly platform when paired with a quality mounting plate and properly torqued hardware.

Sources: Trijicon product specifications, Aimpoint technical documents, Holosun product data, Leupold mounting references, Steiner optics manuals, user discussions from Reddit and pistol-forum communities.