HiViz ARN21 Folding AR Backup Iron Sight Black AR-15 BUIS

The HiViz ARN21 Folding AR Backup Sight delivers reliable secondary sighting when optics fail or batteries die. This low-profile backup iron sight mounts directly to Picatinny rails and folds flat when not in use, preserving your primary optic's sight picture.

What Makes This Different

The ARN21 features a spring-loaded folding mechanism that locks securely in both up and down positions, eliminating wobble that plagues cheaper alternatives. The sight body is machined from 6061-T6 aluminum with a Type III hard anodized finish that resists wear and corrosion. Unlike fixed backup sights that can interfere with optic adjustment or create snag points, this folding design stays out of the way until needed.

Key Features

• Spring-loaded folding mechanism with positive lock positions
• Machined 6061-T6 aluminum construction with hard anodized finish
• Low-profile design clears most optic mounts and accessories
• Tool-free windage and elevation adjustments
• Fits standard Picatinny and Weaver rail systems
• Ambidextrous operation for left and right-handed shooters
• Protective sight ears shield front post from impact damage

Field testing shows the ARN21 maintains zero through repeated folding cycles and withstands recoil from standard .223/5.56 loads. The sight deploys quickly with thumb pressure and locks into position with an audible click. Law enforcement and competitive shooters appreciate the ability to co-witness with red dot optics at lower 1/3 height. The anodized finish resists scratches from gear contact and maintains appearance through extended use.

Technical Specs

• Material: 6061-T6 aluminum with Type III hard anodizing
• Height: 1.5 inches when deployed, 0.4 inches when folded
• Weight: 1.2 ounces
• Mounting: Picatinny/Weaver rail compatible
• Sight radius: Works with standard AR-15 rear sight spacing
• Adjustment: Click-adjustable windage and elevation
• Color: Matte black anodized finish

The HiViz ARN21 provides dependable backup sighting capability without adding unnecessary bulk or weight to your rifle setup. Professional armorers and serious shooters choose this sight for its proven reliability and clean folding action that won't fail when backup sighting becomes critical.