The Magpul MBUS Gen 2 flip-up rear sight is a trusted backup sighting solution for AR-15s and other Picatinny-railed platforms. Whether your primary optic fails mid-range or you're running irons-only on a duty rifle, this polymer-constructed sight deploys and retracts instantly with a single-finger touch on its ambidextrous release tabs. It's been the go-to choice for shooters who demand reliability without the bulk, and for good reason: it works every time you need it.

Built from durable polymer, the MBUS Gen 2 keeps your rifle lightweight while staying tough enough for serious use. The streamlined profile means nothing protrudes to catch on brush, slings, or tactical gear when folded—a real benefit in the field or in close-quarters drill. The spring-loaded mechanism is smooth and positive; deploy and lock happen with equal ease, and retraction is just as reliable. Height over bore matches standard A2 iron sights, so your point of aim transfers predictably if you're switching from primary glass to irons.

The dual-aperture design gives you flexibility: a larger .185" peep for faster target acquisition in low light or close range, and a precision .070" peep for longer-distance accuracy. Windage adjustment is straightforward, and installation is simple—the sight locks to your receiver rail with the included steel crossbolt and consumes less than 1 inch of Picatinny real estate, leaving room for other accessories. It's equally at home on a 16-inch carbine, a rifle-length upper, or any AR platform built to spec.

If you run a quality primary optic but don't have backup irons, or if you're setting up a beater rifle for training or competition, the MBUS Gen 2 is the practical, proven solution.

Key Features

• Flip-up design deploys and retracts with a single-finger touch on either side
• Dual-aperture configuration: large .185" and precision .070" peeps for varied ranges and lighting
• Windage-adjustable for zero customization
• Low-profile polymer construction keeps weight down and snag-free when folded
• Ambidextrous release tabs for left- or right-handed operation
• Height over bore matches A2-pattern sights for familiar sight picture
• Compact footprint uses less than 1 inch of Picatinny rail
• Includes steel crossbolt for secure rail attachment
• Compatible with any Picatinny-railed firearm

Specifications

Manufacturer	Magpul
Product Type	Flip-Up Rear Sight
Material	Polymer
Mounting Standard	MIL-STD 1913 Picatinny Rail
Rail Space Required	Less than 1 inch
Rear Apertures	Large (.185"), Precision (.070")
Adjustment	Windage-adjustable
Release Mechanism	Spring-loaded, ambidextrous
Included Hardware	Steel crossbolt
Height Over Bore	Matches A2 standard

Frequently Asked Questions

Will the MBUS Gen 2 fit my AR-15?

Yes. The sight mounts to any firearm with a MIL-STD 1913 Picatinny rail, including all standard AR-15 and AR-10 receivers, and many other platforms. It requires less than 1 inch of rail space and installs with the included steel crossbolt.

Can I use this sight with a primary optic mounted on the same rail?

Yes. Because the MBUS Gen 2 folds flat and consumes minimal rail space, it's designed to coexist with scopes, red dots, and other optics. It serves as a backup if your primary sight fails or is damaged.

What's the difference between the two rear apertures?

The larger .185" aperture gathers more light and is faster for close-range or low-light shooting. The smaller .070" aperture provides tighter precision for longer-distance accuracy. You can adjust windage independently of which aperture you choose.

Is the release mechanism truly ambidextrous?

Yes. The grooved tabs on both sides of the sight allow left- and right-handed shooters to deploy and retract the sight with equal ease, and the spring-loaded mechanism is consistent from either side.