Magpul® MBUS Back Up Rear Sight, Gen 2

(46 reviews)
Current Stock:
Adding to cart… The item has been added

Magpul MBUS Back Up Rear Sight, Gen 2

The new MBUS (Magpul Back-Up Sight) GEN 2 is a low-cost, color injection molded, folding back-up sight. The dual aperture MBUS Rear Sight is adjustable for windage and fits all MIL-STD-1913 Picatinny rail equipped weapons, but is specifically tailored to the AR15/M16/M4 platform.

Made in the U.S.A.


  • Impact resistant polymer construction provides 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.
  • Clamps to any MIL-STD-1913 Picatinny/STANAG 4694 receiver rail and provides the same height-over-bore as standard A2 irons
  • Protective wings shield the dual flip apertures
  • Detent knob easily and positively adjusts windage


  • Weight, w/ hardware: 1.3 oz.
  • Height above rail, stowed: ~0.51 in.
  • Length, stowed: 2.6 in.
  • Length, deployed: 1.5 in.

NEW Features for GEN 2

  • Reduced size for greater optics compatibility
  • Both small and large apertures are on the same plane


  • 5
    Magpul MBUS great

    Posted by Kevin S on 17th Jan 2013

    Excellent site but since it is a banned weapon system will probably never get to fully get use to it. Great service from your company

  • 5
    Surprising quality at low cost

    Posted by open fire on 12th Jan 2013

    Low profile is a plus. Pop-up works as advertised. Dead on accurate time after time. Not the least bit sloppy. Looks like aluminum from a distance. Perfect for back-up sights on an AR platform. SKD cheapest site around, great customer service.

  • 5
    Good backup sights for the price

    Posted by Jason on 9th Jan 2013

    Does what it's supposed to do.... These sights are backup "irons" for my AR, mounted with an Aimpoint micro. They are just shy of co-witnessing with the Aimpoint, but that wasn't their intended purpose, so it doesn't bother me at all. If the Aimpoint goes down in a fight, it'll be removed (that's why it's mounted with a QD mount). I haven't really abused this rifle, so can't speak to how rugged this plastic sight is (yet). Honestly, if this was my Oh Sh!t rifle, I would have real metal irons mounted. All in all, good back up sights for the price.

  • 5
    Nice, cost effective BUS

    Posted by Rob S on 8th Jan 2013

    They work

  • 5
    Money well spent!

    Posted by Craig Hamilton on 7th Jan 2013

    Bought this to replace the buis thst came on a Sig M400. Mounting it was easy and a trip to range showed it to be dead on right out the package. Much better quality sight than the Sig factory metal sight. Highly recommend. SKD was a pleasure to do buisness with!

  • 5
    Great product and price

    Posted by Unknown on 3rd Jan 2013

    I own a set of these for ever at I own and for the price they can't be beat.

  • 5
    Best backup sight as of 2012!!!

    Posted by Aaron E on 21st Nov 2012

    I first saw this sight on an AR in a sporting goods store last month and was impressed with it's low profile and positive action when releasing the sight. Unfortunately, they did not have any in stock. A lot of my AR accesories are in Dark Earth, and it matches perfectly. I like that the sight has an option to snap down the small reticule and look through the bigger reticule, because it is hard to focus through the smaller one and see anything. I was concerned that the sight might not match my Bushmasters fixed front sight (too high or too low) but it is set at the right height. Windage adjustments are a little firm, but this can be a positive since they will not change unintentionally. Overall, just what I needed to complete my build, and one more way to practice on the range.

  • 4
    No elevation adjustment

    Posted by Michael Kirk on 25th Oct 2012

    Good solid rear sight. I was pleased with it. I've used these for the past couple years and I find them to be among the best. I was a little skeptical of polymer sights in the beginning but I'm a believer now. Plus they are significantly less expensive than other BUIS on the market.

  • 5
    Works perfectly

    Posted by Raoul Duke on 2nd Jul 2012

    Cheap and light weight BUS low profile. Of coase they arent as good looking as a set of Troy flip up sights but they function just the same.