Many AR-15 competitive shooters find they have a far superior sight picture using a hooded rear sight with perfectly round screw in apertures. Compass Lake Engineering's hooded rear sight assemblies are available with half MOA or one fourth MOA of windage adjustment. These sights utilize the existing half MOA elevation adjustment. Both models include a standard .040 inch aperture. Additional apertures are available in .036 inch, .042 inch, .046 inch and .052 inch. These sights are well made, easy to install and legal for service rifle competition for NRA and CMP matches.
Sinclair, Issue:5B, Page:217