The polymer flip up rear sight with windage adjustment mounts onto a 1913 picatinny rail.A flat head screw driver is required to adjust infinite moa by 0.25 moa increments.Unlike other backup sights mft has developed a shroud that shelters the aperture from debris and impact damage when not deployed.Dual peep sight, same plane aperture allows for perfect cowitness.A slim profile allows the sight to sit under most optics.Rear Color: BlackType: Flip Up RearFrame Material: PolymerFrame Color: BlackFirearm Fit: AR-15Base Configuration: Picatinny RailStyle: Flip Up Back Up SightRear Material: PolymerWindage Adjustment: 0.25 MOAElevation Adjustment: 25 MOAFirearm Type: AR Platform