Picatinny Reflex Sight – M21 – 4.3 MOA Bullseye – Quick Release

MEPROLIGHT

Was: $529.99
Now: $429.99

More on the way!

Picatinny Reflex Sight – M21 – 4.3 MOA Bullseye – Quick Release


PLEASE DOUBLE CHECK DETAILS AND FITMENT BEFORE PURCHASE.

The Meprolight M21 is a self-illuminated 1x reflex sight built for fast target acquisition without batteries, switches, or brightness buttons to babysit. This version uses the 4.3 MOA bullseye reticle and includes a quick-release Picatinny rail adapter, making it a strong fit for rifles or shotguns that need a rugged always-on optic with simple mounting and a wide field of view.

If you want a fighting-style reflex sight that stays ready in daylight and low light through fiber-optic and tritium illumination, this is the appeal. The large 30mm window helps keep the sight picture open and fast, especially when shooting with both eyes open.


Fitment

  • Fits firearms or platforms equipped with a compatible Picatinny rail.
  • Includes quick-release Picatinny rail adapter.
  • Works as a non-magnified 1x reflex sight for rifle or shotgun applications where a Picatinny top rail is present.

Does NOT fit

  • Does not mount directly to pistols or optics-cut handgun slides.
  • Does not fit platforms without a compatible Picatinny rail unless a separate correct adapter is used.

What it does

This optic gives you an always-on aiming solution without relying on batteries. During the day, the reticle is illuminated by fiber optics. In low light and darkness, tritium keeps the reticle visible. The bullseye reticle is designed for rapid acquisition, and the large viewing window helps the shooter stay quicker on target without feeling boxed in.


Why it’s worth it

The M21 makes sense for shooters who want a combat-proven reflex sight with less electronic dependency and less fuss. No battery compartment means one less failure point and one less thing to forget. The quick-release mount adds convenience for removal or swapping setups, and the 1x open reflex design keeps things fast at practical distances.


Specs

  • Magnification: 1x
  • Reticle: 4.3 MOA Bullseye
  • Reticle Color: Amber
  • Objective / Window Size: 30mm
  • Illumination Type: Fiber optic by day, tritium by night
  • Power Source: Self-illuminated / no batteries required
  • Mount Type: Picatinny quick-release adapter
  • Finish / Color: Black

What’s included

  • Meprolight M21 reflex sight
  • Quick-release Picatinny rail adapter

Install notes

Mount to a true-spec Picatinny rail and confirm the quick-release hardware locks up correctly before live fire. After installation, verify zero on your actual firearm and ammo setup. As with any optic mount, re-check retention after initial range use.


Verify before you buy

Verify your firearm has the correct Picatinny rail interface and that this style of non-magnified reflex sight matches your intended use. This is a rail-mounted optic, not a direct pistol-slide optic. If you need magnification, enclosed-emitter protection, or a different mounting footprint, this may not be the right play.

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