Magpul MBUS 3 Sight Rear Sight Black

The Magpul MBUS 3 Sight Rear Sight in Black represents the latest refinement in the industry-standard MBUS backup sight line, combining the proven performance of its predecessors with a more compact profile and refined ergonomics. This rear backup sight is engineered for operators who demand a lightweight, reliable secondary aiming system that deploys instantly when primary optics fail or need backup verification. At just 0.55 inches when folded and 30 grams with hardware, the MBUS 3 Rear Sight delivers minimal weight penalty while maintaining the sight picture repeatability critical for mission-ready firearms.

Built from impact-resistant polymer rather than metal, the MBUS 3 maintains mechanical robustness while reducing reciprocating mass on the rifle's top rail—a meaningful advantage during rapid shooting transitions. The sight's 1.38-inch width accommodates standard Picatinny rail mounting without interference from most mid-range optic housings. The proven detent mechanism locks the sight securely in both folded and deployed positions, preventing unwanted collapse under recoil or during prone shooting. Sight picture clarity and target acquisition speed are uncompromised compared to full-size backup systems, making the MBUS 3 a logical upgrade for rifles already running lighter combat optics or magnified scopes that benefit from co-witnessed iron backup.

This rear sight pairs seamlessly with the Magpul MBUS 3 front sight to create a complete backup iron sight (BUIS) set, though it operates equally well with existing front sight systems from Magpul or other manufacturers. Law enforcement patrol rifles, military issued carbines, civilian defensive shooters, and range trainers rely on the MBUS 3 line for its balance of compactness, affordability, and documented durability across extended service. Whether mounted on a piston AR-15, direct impingement carbine, or precision rifle backup rail, the MBUS 3 Rear Sight delivers the function and predictability professional users expect without the bulk or cost of premium tactical sights.