AR-15 Adjustable Rear Sight

We have very affordable and dependable AR15 Backup Rear Sights for sale. This is an A2 Style Adjustable Iron Sight for AR-15 M4 Flattop Rifle.  This NcStar MARDRS is compact enough that it does not take up much of your Picatinny rail space.  You can have a backup rear sight ready to go at the moment's notice and still have space for a reflex, red-dot or holographic optic on your AR15 upper receiver.

In stock


 Secure Online Payments

cc-visa  cc-mastercard  cc-amex  cc-discover

American Owned and Operated


20+ Years In Business


Returns Accepted


Ships from Pennsylvania


This AR-15 Back-Up Rear Sight should fit all AR15, M4 and M16 flattop picatinny rail upper receivers.  It is fully adjustable for elevation and windage with knurled click adjustable controls.  We also have M-16/AR-15 Flip Up Rear Sight if you are looking for another type of AR15 Backup Iron Sight.

  • Matte Black in Color.
  • Made of Steel and Aluminum.
  • A2 rear sight assembly with large and small rear aperture.
  • Large steel thumb nut and steel rail clamp for positive and secure attachment to your upper receiver.
  • Made by NcStar.
  • If you need a tool to sight your AR-15 Rifles, we have AR15 front sight adjustment tools for sale.

    More Information
    Overall Rating
    Very Pleased
    Review by Noam H.
    Delighted with this purchase.
    Overall Rating
    Excellent AR15 rear sight
    Review by Liam F.
    Price is wonderful and shipping was speedy.
    Overall Rating
    Thanks keepshooting
    Review by Quinten S.
    Received in four days after ordering. Will be back to shop from Keepshooting.
    Overall Rating
    Thanks KS
    Review by Schad T.
    Drop In replacement rear sight for my AR15.
    Overall Rating
    Review by Kennon M.
    Finest AR15 rear sight for the price from a terrific company. Thank you keepshooting!
    Overall Rating
    THANKS keepshooting
    Review by Winthrop J.
    Would Recommend this part
    Overall Rating
    Excellent Price
    Review by Otis O.
    Best AR15 rear sight for the price shipped by a terrific company. Thank you ks!
    Overall Rating
    Great for me
    Review by Shamell D.
    Best AR15 rear sight for the price shipped by a terrific company. Thank you KS!
    Overall Rating
    Review by Lashaun Z.
    Delighted with this transaction.
    Overall Rating
    Exactly as described.
    Review by Varun P.
    These replacement parts are awesome. Would definitely recommend.
    Write Your Own Review
    You're reviewing: AR-15 Adjustable Rear Sight
    Your Rating:

    You submitted your review for moderation.

    Customers Also Bought

    Navigating through the elements of the carousel is possible using the tab key. You can skip the carousel or go straight to carousel navigation using the skip links.
    AR-15 Rear Flip-Up Sight
    4.4 (100)
    AR-15 A2 Flash Hider
    4.5 (71)
    Anderson Manufacturing Bolt Carrier Group - AM08ASSM
    4.8 (5)
    AR15 Low Profile Gas Block
    4.55 (75)
    AR15 / M16 Flip Up Front Sight
    4.45 (429)
    AR15 / M16 Front Sight Tool
    4.5 (478)