Optimized for the AR Type rifle, the Rotary Diopter Rear Sight provides four site stations (CQB, 100m, 200m, 300m) with toolless windage and elevation adjustment. Includes riser block for correct sight alignment for AR type rifles. Features: 4 sight stations (CQB, 100m, 200m, 300m) for accurate engagement at varying distances. Tool-less windage and elevation adjustment. Optimized for M855 and M193 ammunition. M1913 compatible mounting system. Durable steel construction.