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Magpul
Overview
The Magpul MBUS Rear Flip-Up Back Up Sight Gen 2 in black is a polymer folding sight designed for quick deployment and reliability in various shooting conditions. This rear sight pairs seamlessly with a front sight to provide a robust backup aiming solution, ensuring that your rifle remains functional even if your primary optics fail. Commonly found in tactical and multi-purpose builds, this sight is valued for its lightweight construction and ease of use.
Magpul MBUS Rear Flip-Up Back Up Sight Gen 2 Black is the seventh most added iron sight on GunPartPicker so far in September 2026, behind the Magpul MBUS PRO AR-15 Iron Sight Front Flip Up - MAG275, with about 2% of all iron sights added to builds. Up from #8 in August. Builds with this iron sight are mostly chambered in 5.56 NATO (60%, then .223 Wylde 20%), split between carbine-length (50%) and mid-length (33%) gas systems, and nearly all AR-15.
Availability is good: it was in stock at one retailer or another nearly every day in August 2026, and today only Optics Planet has it in stock. Prices barely moved in August 2026, holding around $37.95, so there haven't been real sales lately. Buying today, the lowest price is $35.95 at Optics Planet, which matches the best price we saw in August.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 35 retailers
We ranked every iron sights by how often it shows up in real builds on GunPartPicker.
Read the guide: AR-15 Iron Sights Guide →The part most often added in each category by the 65 builds that include this one
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Aggregated and anonymized data showing how builders use this product
Builds in the community that include the Magpul MBUS Rear Flip-Up Back Up Sight Gen 2 Black
| Build | Parts | Total |
|---|---|---|
 | 30 | $5283.47 |
| 26 | $5778.05 |
 | 20 | $3994.99 |
 | 24 | $1170.59 |
| 16 | $1920.76 |
 | 16 | $1661.22 |
 | 23 | $2762.64 |
1 global rating
Top reviews
Magpul MBUS rear Gen 2 is a backup sight that mostly does its job. Mine needed a follow up zero session after the first range trip, the windage drum had moved a hair from the initial setting. Now its solid. Worth knowing to do two zero sessions to confirm.
