Magpul MBUS Pro - Magpul Back-Up Sight Set - Front & Rear w/ Free Silicone Gun & Reel Cloth All steel construction Case hardened and finished with a ferritic nitrocarburizing process for extreme resistance to wear and corrosion Front Sight Mounts on any MIL-STD-1913 Picatinny/STANAG 4694 rail including receiver-height gas blocks; Rear Sight Mounts on any MIL-STD-1913 Picatinny/STANAG 4694 rail Positive detents keep the MBUS PRO Front and Rear at standard sight height when deployed, and so low when they are stowed that you'll never notice them until they're needed Includes Free Silicone Gun & Reel Cloth