Magpul® MBUS Back Up Rear Sight, Gen 2

(46 reviews)
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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
    great for back ups

    Posted by Brandon on 30th Apr 2012

    Great for what they serve and thats back ups. Their priced well too. Why spend 100 a piece for buis when alk they do is sit on the rail?

  • 5
    Quality and affordability

    Posted by Darren Railey on 27th Mar 2012

    This rear MBUS is a great product. It was easy to install and easy to adjust. Works great and at a much more affordable price then that of the top end sights.

  • 5

    Posted by DARRIN M on 12th Mar 2012

    The magpull MBUS rear sight is great,It has a nice low profile when stowed. It is alot more sturdy than what i thought,So far it holds a zero very well, And adjusting it is pretty easy. I also like the spring up feature it has, overall im very happy with it. SKD IS THE BEST!

  • 5
    Best BUIS I've found ... and I've tried a lot

    Posted by A4Driver on 8th Mar 2012

    Great BUIS -- they live up to all the reviews. Easy co-witness through any red dot I'm familiar with and use. Remember, the Magpuls are NOT National Match sights, but that's not what we're talking about .. right?? SKD Tac. shipping and COMM was way above average, too.

  • 5
    Great sight

    Posted by Hi Five on 29th Feb 2012

    Sight is very durable, stays locked down till you need it. Very strong spring pops it up quick and keeps it up, no slop. Should last the life of the rifle.

  • 5
    Magpul MBUS Back Up Rear Sight, Gen 2

    Posted by Jericho on 22nd Feb 2012

    Sight works perfect on a Flat Top 14.5" BCM upper with a Aimpoint Micro T-1. For being a polymer it feels really good, has a positive lock when down and up. Tier 1

  • 5
    MBUS Sights on 9mm Carbine

    Posted by Joseph on 16th Feb 2012

    I purchased the front and rear MBUS sights to put on a Hi Point 9mm carbine with the ATI stock. I had to set the front sight as low as it would go, but the sights were dead on. Using these sights has made with carbine has made it very easy to use.

  • 5
    MBUS BUIS Gen 2

    Posted by Unknown on 11th Feb 2012

    THis is exactly what I was looking for, for a super low price. Came very fast.

  • 5
    Great sight, good price

    Posted by Mike in TX on 8th Feb 2012

    I think most people know the Magpul MBUS is an excellent budget flip-up sight - well-engineered and rugged. This is my first one and I'm not at all disappointed. It mounted quickly and easily and when I took it to the range it was dialed in nicely with the standard front sight tower. I'm running an Aimpoint-stly red dot, and the cowitness was perfect - the red dot sitting right atop the front sight post. Shipping was fast and the price was good. Recommended.