For the best selection of AR aftermarket parts and accessories, look no further than Palmetto State Armory! Strike Industries R.EX Riser is a lightweight, low profile riser for AR style firearms that weighs 2.0 ounces total and provides the ideal height for co-witnessing. The REX riser offers versatility with mounting options. Achieve ideal height for co-witnessing when paired with the Strike Industries Reflex Exoskeleton mount with both A2 height, or Sidewinder sights (without a spacer). Although designed to be used with the REX mount (adds 0.200 inches of height to either mounting combo), the R.EX riser can also be mounted using any universal M1913 Picatinny rail and requires 5 rail sections of space to properly mount.