When your primary optic fails or you need a reliable backup aiming system, Meprolight USA flip-up backup sights offer a proven solution for AR-15 shooters who demand dependability without complexity. These self-illuminated tritium sights combine low-profile construction with the durability to serve as either a secondary sight system or a standalone option on your rifle. Built around a spring-based locking mechanism that resists deformation, they're engineered to function reliably in the field without the need for tools or adjustment hassles.
The FUBS design leverages a blend of fiberglass-reinforced polymer and metal components, keeping overall weight minimal while maintaining the rigidity necessary for consistent aiming. The green tritium lamps provide self-illumination in low-light conditions, eliminating battery dependency and simplifying your gear. Because they mount directly to any MIL-STD 1913 Picatinny rail, integration with your existing AR setup is straightforward—no gunsmithing required.
Meprolight backs the tritium luminance with a 12-year warranty, reflecting confidence in the night sight performance. For hunters working dawn and dusk, home-defense rifles, or range guns where redundancy matters, these flip-ups serve as genuine insurance against optical failure. Rugged, compact, and ready to deploy exactly when you need them.
| Brand | Meprolight USA |
| Model | 404100 FUBS |
| Type | Self-Illuminated Flip-Up Backup Sights |
| Tritium Color | Green |
| Material | Fiberglass-reinforced polymer and metal |
| Mounting Standard | MIL-STD 1913 Picatinny Rails |
| Locking Mechanism | Spring-based |
| Configuration | Front and rear pair |
| Tritium Warranty | 12 years |
Yes. The 404100 FUBS mounts to any Picatinny rail system (MIL-STD 1913 standard), which is standard on modern AR-15 upper receivers and rail systems. They come as a front and rear pair ready to install without tools.
No. The green tritium is self-illuminated and requires no power source. The tritium will provide low-light aiming capability and maintains luminance throughout the 12-year warranty period.
These sights can serve as either a primary aiming system or a backup. Many shooters use them as secondaries behind a mounted optic, but they're robust enough to function as a stand-alone sight solution if you choose.
No. The manual adjustments require no tools, and the spring-based locking mechanism allows you to flip them up or down by hand. The design prioritizes simplicity and field reliability.
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