• Light weight and resists operational abuse
  • Spring-loaded flip up sight easily activated from either side or by pressing the top
  • Detent and spring pressure keeps sight erect but allows for unobstructed folding under impact, etc
  • Fits any Mil-Spec 1913 Picatinny and STANAG 4694 receiver rail and provides the same height-over-bore as standard A2 irons
  • Protective wings shield the dual, same plane flip apertures
  • Sight can still be folded with either large or small aperture in position
  • Detent knob easily and positively adjusts windage
  • Available in Black, Flat Dark Earth, and OD Green
  • Made in the U.S.A.


  • Material: Polymer
  • Finish: Black, Flat Dark Earth, or OD Green
  • Weight: 1.3 oz.
  • Height Above Rail, Stowed: ~0.51"
  • Center of Aperture To Top of Rail: 1.42"
  • Length, Stowed: 2.6"
  • Length, Deployed: 1.5"


  • Any firearm with top Picatinny Rail


Whether you're looking for some iron sights to back up your optic or just a reliable set of primary sights, Magpul has you covered with their Magpul Back Up Sight (MBUS) Gen2.

This rear back up sight is made of impact-resistant polymer for maximum durability. It can fold down and stay out of the way if necessary, and you can pop this spring loaded sight back into the upright position in an instant by pressing down on the top of the sight!

The Magpul MBUS rear sight features three different apertures, allows for accuracy at mid to long ranges and quick sight alignment for CQB. You can easily adjust the sight for windage with the knob located on the side of the sight. Whether you use your AR-15/M-16 for work, competition, or recreation, you won't find a better rear back up sight than the MBUS from Magpul!

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Reviews (7)

  • Mag Pul Back Up Sights

    Posted by Nathan Adams on 8th Jul 2022

    Have done 3 builds so far. The first one used Mil-Spec type removable aluminum sights. The last 2, I have used these. WISH I had put these on the first build I did. They work PERFECTLY with Blitzkrieg Triangle Front Sights, where as the other front sight was NOT Mil-Spec as they claimed. These just ROCK!!!!!

  • Inexpensive Reliable Sight

    Posted by R. Escobar on 14th Sep 2021

    This sight is an inexpensive option for an excellent light weight, quality built product. I have these on all my rifles and though they are not metal, they do the job. Magpul quality is always excellent.

  • Perfect Companion!

    Posted by Greg on 21st Sep 2020

    Great Sight! Couldn't be better! Robust, Easy to Use, Looks Great!!!!

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