Quick answer: Want sights that glow in the dark? Meprolight FRBS tritium. Want them beside your optic, ready with a roll of the rifle? FAB Defense FRBS 45° offset. Want them low and simple? CAA low-profile flip-up. All mount on a Picatinny rail.
BUIS (backup iron sights) live folded down until the day your red dot quits. That day usually picks a bad moment.
Our Picks
| Sights | Type | Best for |
|---|---|---|
| Meprolight FRBS | Flip-up, tritium | Low light: 4 tritium vials rear, 1 front |
| FAB Defense FRBS offset | 45° offset, folding | Keeping your optic on top |
| FAB FBS + RBS | Flip-up front and rear | Classic BUIS, two rear apertures |
| CAA low-profile | Flip-up front and rear | Low profile, quarter-turn post lock |
| CAA FRS rear | Rear flip-up | Push-button deploy, large aperture |
Tritium: Meprolight FRBS
Meprolight FRBS Tritium Flip-Up Sights
Four tritium vials in the rear and one up front glow without batteries, with an orange ring for daylight. Swiss tritium with a 12-year guarantee. Tool-free elevation.
How tritium works: tritium night sights explained. Tritium products ship to US addresses only.
Offset: FAB Defense FRBS
Mounted at 45°, they sit beside your optic instead of behind it. Roll the rifle and they're there. Tool-free rear windage and front elevation; right or left hand.
Classic Flip-Up: FAB FBS and RBS
The RBS rear has two apertures: 3 mm for low light and 1.5 mm for precision. Pair it with the FBS front and its angel-wing shroud.
Co-Witness in One Paragraph
Co-witness means your iron sights line up in the same window as your red dot. With flip-up sights you keep them folded and only deploy them when you need them, so they don't clutter the optic.
FAQ
What are flip-up backup sights?
Iron sights that fold flat on your rail and flip up when your optic fails.
Do I need backup sights with a red dot?
They're cheap insurance: batteries die and optics can break.
What are offset backup sights?
Sights mounted at 45° beside the optic, so you roll the rifle to use them without removing the optic.
Do tritium backup sights need batteries?
No. Tritium glows on its own; Meprolight guarantees the FRBS tritium for 12 years.
The Bottom Line
Low light: Meprolight. Optic on top: FAB offset. Simple and low: CAA.
