The HIVIZ ARN21 folding back up sight for AR-15 delivers a compact, reliable green iron sight designed to mount on a Picatinny rail and complement an A2 front sight, offering rapid target acquisition and a secure foldable profile that minimizes snagging when not in use. Engineered as a versatile front/rear option for long gun setups, this folding back up iron sight brings sturdy construction and precise alignment to your rifle, ensuring you retain sight picture under dynamic field conditions while maintaining a slim, low profile during travel or storage. With its durable build and easy deployment, shooters can quickly deploy true alignment for rapid shots in any light, and then fold the sight tight to the rail for transportation, hunting, or competition scenarios. The green finish enhances visibility in varied environments and the sights Picatinny compatibility guarantees straightforward installation across standard AR platforms, making it a practical addition for shooters seeking an unobtrusive, dependable backup that complements a primary optic system without complicating the rifles geometry.