Magpul MBUS Rear Flip-Up Sight - Flat Dark Earth (FDE) for AR-15/M16

The Magpul MBUS Rear Flip-Up Sight in Flat Dark Earth is a backup iron sight built to stay out of the way until you need it. Designed as a secondary aiming option for AR-15, M16, and other Picatinny-railed rifles, this rear flip-up sight deploys with one motion and stows flat when your primary optic is doing the work. Its low-profile, streamlined design won't catch on brush, slings, or gear in the field—and it locks securely in place once deployed.

The ambidextrous release mechanism means you can flip the sight up or down from either side of the rifle, which matters when you're moving fast or shooting from an unconventional position. The spring-loaded action is intuitive: tap the grooved tabs to deploy, tap them again to fold it down. Since it uses less than an inch of Picatinny rail space, it won't crowd your handguard or top receiver, leaving room for your primary optic, laser, light, or other mission-critical gear. The steel crossbolt keeps everything locked tight with zero wobble.

The rear sight ships with two different apertures—a larger .185" peep for quick target acquisition in lower light or stress situations, and a smaller .070" peep for precision work at distance. Windage is adjustable, so you can dial in your backup zero once and rely on it. Magpul engineered the sight to match the height over bore of a standard A2 iron sight, which means it'll cowitness with most modern optics if you want that added layer of redundancy.

Whether you're running a modern optics-first setup or just want a fail-safe backup, the MBUS rear sight is trusted by shooters who understand that gear needs to work when called upon and stay invisible when it isn't. The Flat Dark Earth finish blends with most tactical and hunting platforms.

Key Features

• Ambidextrous flip-up design with spring-loaded deployment
• Dual apertures: .185" and .070" peep options for versatile aiming
• Windage-adjustable for zero customization
• Ultra-compact footprint: less than 1" of Picatinny rail space
• Streamlined contours won't snag on gear or brush when folded
• Low-profile polymer construction with steel crossbolt retention
• Cowitness height matches standard A2 iron sights
• Flat Dark Earth color for tactical and hunting rifles

Specifications

Frequently Asked Questions

Will the MBUS rear sight work on my AR-15 with a scope or red dot mounted?

Yes. The sight is designed as a backup option and cowitnesses with standard optics. Its ultra-compact footprint uses less than an inch of rail space, so it won't interfere with most primary optics. When folded, it sits completely out of the way.

Can I adjust the windage on this rear sight?

Yes, the MBUS rear sight is windage-adjustable, allowing you to dial in your zero. It ships with two apertures—a larger .185" and a smaller .070" peep—so you can choose based on your lighting conditions and shooting distance.

Is the release mechanism truly ambidextrous?

Absolutely. The spring-loaded tabs can be deployed or retracted from either side of the sight, making it equally fast whether you're right- or left-handed or shooting from an unconventional position.

What comes in the box?

The Magpul MBUS Rear Flip-Up Sight includes a steel crossbolt for secure mounting to any MIL-STD 1913 Picatinny rail.