The next evolution in our MBUS (Magpul Back-Up Sight) line, the MBUS 3 incorporates the best features, strengths and value of our original MBUS and MBUS Pro Sights in a feature-packed back-up sight system. Significantly reduced in size from the MBUS, it sits at just 0.55" high when folded, 1.38" at its widest point, and weighs a scant 30 grams with hardware. Its aesthetics are derived from the MBUS Pro, but the MBUS 3 Rear Sight is constructed of our impact-resistant polymer, making it lightweight and extremely durable. Featuring the same spring-loaded technology as its predecessor, they can be deployed with an ambidextrous push-button. The MBUS 3 Rear Sight sits at standard AR-height when deployed and includes a windage adjustable, rapid-select aperture system.