ProMag PM238 AR-15/M16 Flip-Up Front Sight for Gas Block Mount, Black Designed to be mounted on M1913 Picatinny rails This sight may be paired with model PM136, PM137, PM200 rear sights mounted to AR-15 / M16 flat top A3 upper receiver rifles and carbines Sight is locked in place via a spring loaded plunger Elevation-zero is accomplished as with any GI-style front sight, in 1.25-moa increments (+/-) Black Finish