The HiViz AR Vertical Tritium Front Sight Post (brand part no. ARN101) is a direct replacement for the standard AR-15 A2 front sight post, swapping in a self-illuminating green tritium vial that doesn’t rely on ambient light to glow. Because it’s a true tritium light source rather than a fiber optic, it performs identically in bright daylight or a darkened room, making it a genuine low-light upgrade rather than a daytime-only accessory. The post is fully interchangeable with the factory A2 post and includes both an adjustment tool and a detent for a secure, correct installation. It’s a focused upgrade for AR owners who want a reliable aiming reference even after the sun goes down.

Key Specifications

• Uses a tritium/green self-illuminating vial rather than a fiber optic rod, so it glows without ambient light.
• Built as an AR-15 A2 front sight post replacement, fitting the standard A2 front sight housing.
• Fully interchangeable with the factory A2 post for a direct swap.
• Ships with an adjustment tool and detent included, everything needed for correct installation.

Frequently Asked Questions

Does this need light to glow? No, it uses a self-illuminating tritium vial that works the same in daylight or darkness.

Does this fit a standard A2 front sight? Yes, it’s designed as a direct, interchangeable replacement for the factory A2 front sight post.

Is installation hardware included? Yes, an adjustment tool and detent ship with the sight post.

Shop more front sight options in our gun sights category from HiViz.

Buy the HiViz AR Vertical Tritium Front Sight Post

A front sight that only works when the sun is up isn’t much of a backup, and this tritium post fixes that with a true low-light aiming point. Order it from our Lubbock, Texas gun shop for fast, direct shipping.