The retro A1 rear sight assembly serves as a premium enhancement for AR-style rifles. It boasts a robust and streamlined design, incorporating a retro style rear sight windage drum to facilitate precise aiming. Whether utilized at the shooting range or in the field, this sight ensures confident and accurate shooting. The package includes the UR-09-E3-R retro style rear sight windage drum, UR-11-E3 detent, UR-12-E3 detent spring, UR-13-E3 aperture, UR-14-E3 windage screw, UR-16 base roll pin, and UR-28 flat spring