A/T Optic Riser 525-13 is approximately 5-3/4 long and covers the entire length of an upper receiver and offers one more recoil slot than the upper. This riser has 13 recoil slots (14 lugs). It can be used with any combination of sights, NVG, or thermal which would fit on an upper receiver and the additional slot gives the user some spacing flexibility. Ideal for layering magnifiers and other enhancement systems with red dot optics, BCM A/T Risers offer the potential for a more capable platform that can improve threat identification in complex settings. Optimized for close combat ranges, the BCM A/T Riser creates a platform that raises the centerline of attached optics and magnifiers by approximately 1/2 inch. This additional height enhances the trained end users situational awareness, and further, makes it possible for them to take better aimed shots if they are using the optic in conjunction with night vision or other PPE systems. Interfacing with the upper receiver using the same low-profile A/T system used in our Optic Mounts, not only reduces snag hazards but makes the entire length of rail usable for either bolt-on or QD attachments. Further, the low profile A/T interface enables mounting accessories with Mil-Std 1913 attachments anywhere on the stalk of the riser platform allowing end users to fine tune placement of optics, magnifiers, and other accessories. Each A/T Riser is machined from aircraft aluminum alloy, hard coat anodized per Mil-A-8625F. The steel alloy clamp is hardened with Nitride coating for maximum strength. Finally, each Riser features multiple integral recoil lugs to mitigate recoil and counter recoil to preserve your zero and ensure no fail shots are placed where intended by the trained rifleman. A/T (Angled Torque) mounts employ angled torque through a patented* clamp which applies triangulating force to create a stronger and more reliable lock up of the mount onto the end users rail.