If you have a flat top AR-15, the the Sun Optics AR-15 Flat Top Front and Rear Sights are what you need. These sights are constructed from aluminum and come in a black finish. The rear sight has windage and elevation adjustments.
Specifications and Features:
AR-15 Flat Top Front and Rear Sight
Windage/elevation on rear sight
Fits Picatinny/Weaver type rails