Magpul MBUS Rear Flip-Up Back Up Sight Gen 2 Black. These AR 15 Parts from Magpul Industries are spring loaded for fast engagement and easily clamp for Mil Spec 1913 Picatinny rail systems. The Magpul MBUS Rear Gen II Flip-Up Back Up Sight features a dual aperture and is easily adjustable for windage. Impact resistant polymer is durable and dependable in most demanding situations. The Magpul MBUS Rear Gen 2 Flip-Up Back Up Gun Sight proves to be an essential part of an operator's weapon system. Specifications for Magpul Industries MBUS Rear Flip-Up Back Up Sight Gen 2: Manufacturer: Magpul Industries Condition: New Sight Mounting Orientation: Top Mounted Sight Position: Rear Gun Model: AR-15 Deployable: Yes Fabric/Material: Polymer Height: 0.51 in Length: 1.5 - 2.6 in Hand: Ambidextrous Weight: 1.3 oz Attachment Type: Picatinny Adjustment Click Value: 0.5 MOA Features of Magpul Industries MBUS Rear Flip-Up Back Up Sight Gen 2: The MBUS (Magpul Back-Up Sight) is a low-cost color injection molded folding back-up sight. The dual aperture MBUS Rear Sight is adjustable for windage and fits most 1913 Picatinny rail equipped weapons but is specifically tailored to the AR15 / M16 platform. . SPRING-LOADED FLIP UP SIGHT Spring-loaded flip up sight easily activated from either side or by pressing the top Protective wings shield the dual same plane flip apertures Sight can still be folded with either large or small aperture in position Detent knob easily and positively adjusts windage IMPACT-RESISTANT POLYMER CONSTRUCTION Polymer construction provides light weight and resists operational abuse DETENT AND SPRING PRESSURE KEEPS SIGHT ERECT Detent and spring pressure keeps sight erect but allows for unobstructed folding under impact etc. CLAMPS TO MOST MIL-STD-1913 PICATINNY RAILS Clamps to MIL-STD-1913 Picatinny/STANAG 4694 receiver rail and provides the same height-over-bore as standard A2 irons Package Contents: Magpul MBUS Rear Gen II Flip-Up Back Up Sight What firearm models does the manufacturer say Magpul Industries MBUS Rear Flip-Up Back Up Sight Gen 2 is compatible with? The manufacturer suggests that Magpul Industries MBUS Rear Flip-Up Back Up Sight Gen 2 is compatible with AR-15