Hi-Viz ARN21 Folding AR Back-Up Sight — AR-15 Tritium

The Hi-Viz ARN21 is a folding back-up sight set designed for AR platforms and specified for AR-15 A2 front sight application. It combines a vertical tritium front sight post with a dual-aperture rear sight that offers both elevation and windage adjustments. The set is made to fit 1913 Picatinny rails and stows flat when not in use. Sight elements are supplied in red/green configuration for rapid visual reference in varying light conditions.

Key Specifications

• Designed for the application AR-15 A2 FRONT SIGHT.
• Fits the platform identified as AR-15.
• Compatible with the AR Platform.
• Features a Folding Back Up Sight style for compact stowage.
• Sight markers are supplied in RED/GREEN coloration.
• Includes FOLDING AR BACK UP SIGHT SET, VERTICAL TRITIUM FRONT SIGHT POST, DUAL APPERTURE REAR SIGHT, ELEVATION AND WINDAGE ADJUSTABLE, FITS PIC RAILS.
• Overall dimensions listed as 1.35 X 3.85 X 6.60.
• Components are marked as Yes for interchangeability.
• Configured as a Front/Rear sight set.
• Marketed under the model designation Back Up Iron Sight.

Purpose-built as a reliable mechanical backup for modern sporting rifles, the ARN21 offers a practical mix of low-light capability with tritium illumination and precise, user-adjustable rear sighting. Its folding design keeps optics and rails clear when primary sights are in use, while the dual-aperture rear and windage/elevation adjustments provide flexible aiming options when deployed. Suitable for users seeking a compact, robust iron sight solution for AR-15 platforms.