Manufacturer: ProMag PM136
Low profile flip rear sight attaches to AR-15, M16, and M4 flat top upper receivers. May be used as a back up rear sight or a lightweight rear sight to co-witness with red dot or holographic sights. Locks in upright position and a spring loaded release button must be depressed to flip it down. This sight has both 0.199 inch and 0.73 inch apertures on the same sighting plane. This allows both apertures to be sighted to the same point of impact. Four apertures so that rotating the dial in either direction brings the next size aperture to view. The windage is adjusted using a standard A2 windage adjustment drum. One click allows 0.55 MOA change on rifles and 0.65 MOA change on carbines. Constructed of both black oxide carbon steel and black anodized aircraft grade aluminum. Mounted to the rail via a locking bar and secured with a cross slotted, knurled thumb screw.