Mako Group Folding Back-Up Sight- Rear (Black) Every Weapon With An Optical Sight Should Have An Auxiliary Sighting System. If Your Optic depends On Batteries, Auxiliary Sights Are An Absolute Necessity. Features: - Designed For M4, M16 And AR-15 Rifles, The KPOS System, And Other Weapons With Same-Plane Mounting locations And Similar Sight Height. - Finger-Adjustable For Windage. - Low-Profile, Lightweight Design. - May Be Used as Primary Or Secondary Sights. - Ambidextrous Deployment And Control. - High-Grade Polymer And Metal Construction. - Spring-based Locking Mechanism Will Not Break Or Deform. - Mounts To Mil-Std-1913 Picatinny Rails. - Rear Sight Weight: 1 Oz. - Carries Our Lifetime Replacement Guarantee!