Description
The Arex Delta L Gen2 OR 9mm 4.5 in Optic Ready is a striker-fired, modular pistol built for EDC guys who want factory optic compatibility without the wait. The 4.5-inch barrel gives you a longer sight radius and softer recoil impulse than the standard Delta, while the optic-ready slide ships with a plate kit for RMR, Holosun, and other popular footprints. This is a daily carry gun that adapts to your grip, your optic, and your carry style — right out of the box.
| Manufacturer | Arex |
|---|---|
| Model | Delta L Gen2 OR |
| Material | Steel slide, polymer frame (per manufacturer specs) |
| Compatibility | RMR, Holosun K-series, and other micro red dot footprints (plate kit included) |
| Finish | Nitride |
| Weight | 28.2 oz (unloaded, per manufacturer specs) |
| Condition | New |
Key Features
- Optic-Ready Slide with Plate Kit — Why it matters: You can mount your RMR or Holosun 507K without sending the slide to a machine shop. The included plates cover four common footprints, so you’re not hunting down extras.
- Removable Front and Rear Frame Inserts — Why it matters: The fire control unit drops out as a module, letting you swap frame sizes or colors without buying a whole new gun. That’s modularity that saves you money over time.
- Ambidextrous Slide Stop and Magazine Release — Why it matters: Lefties and righties get the same fast reloads and slide lock. No need to swap parts or train around a one-sided design.
- Interchangeable Backstraps (Three Sizes) — Why it matters: A proper grip fit means faster follow-up shots and better recoil control. Swap from small to large in seconds using the included punch.
- 4.5-Inch Barrel with 1:10 Twist — Why it matters: That extra half-inch over the standard Delta gives you a velocity bump for defensive 9mm loads and a longer sight radius for precision at the range.
Who It’s For
This pistol is for the EDC guy who wants a factory optic cut on a full-size frame but doesn’t want to drop Agency Arms money. It’s also for shooters who like to tinker — the removable fire control unit and backstrap system let you dial in the fit without a gunsmith. If you carry appendix, the 4.5-inch barrel still conceals under a good holster and a cover garment.
Pros & Cons
- Pro: Factory optic cut with four plates included — saves $100+ on milling.
- Pro: Interchangeable frame inserts let you swap colors or replace worn parts without buying a new lower.
- Pro: Ambidextrous controls work for left-handed shooters out of the box.
- Con: Trigger pull is heavier than some aftermarket options — expect a 5.5–6 lb break out of the box. A trigger job or upgrade kit can fix that, but it adds cost.
Comparison: Arex Delta L Gen2 OR vs. Zev OZ9 vs. Lone Wolf Dusk 19
| Feature | Arex Delta L Gen2 OR | Zev OZ9 | Lone Wolf Dusk 19 |
|---|---|---|---|
| Price | $465 | $1,299 | $499 |
| Optic Cut | Factory (4 plates included) | Factory (RMR only) | Factory (RMR only) |
| Modularity | Removable fire control unit + backstraps | Removable fire control unit + backstraps | Fixed frame (no FCU) |
| Barrel Length | 4.5 in | 4.49 in | 4.02 in |
| Weight (unloaded) | 28.2 oz | 27.5 oz | 25.6 oz |
| Warranty | Lifetime (per Arex) | Lifetime | 1 year |
FAQ
What optics fit the Arex Delta L Gen2 OR?
The included plate kit supports RMR, Holosun K-series (407K/507K), Docter/Noblex, and Shield RMSc footprints. Check the manual for torque specs — 15 in-lbs on the optic screws.
Is this gun compatible with Glock holsters?
No. The Delta L Gen2 has a unique trigger guard and slide profile. You’ll need a holster specifically molded for the Arex Delta series. Companies like Red Hill Tactical and ANR Design make them.
Can I swap the frame inserts without tools?
You’ll need a punch or small screwdriver to push out the retaining pins. The process takes about two minutes once you’ve done it once.
What’s the difference between the Delta L and the Delta M?
The Delta L has a 4.5-inch barrel and full-size grip. The Delta M uses a 4-inch barrel and compact grip. Both use the same FCU, so you can swap slides and frames between them.
✓ Nationwide delivery (all 50 states)
✓ Ships 1-2 business days
✓ 30-day returns
✓ Secure checkout
Explore more: Semi Auto Handguns | Optic Ready Pistols | Arex Firearms
Last updated: April 2026
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