The Daniel Defense 1 O'clock Offset Rail is optimized for mounting miniature red dot optics in the 1 O'clock (right-hand) or 11 O'clock (left-hand) positions for quick, non-magnified, transitions when employing magnified primary optics on AR-type rifles with MIL-STD-1913 rails. The geometry allows for zero cheek-weld shift during the transition. This facilitates very fast transitions from magnified to non-magnified optics, and back. The 1 O'clock Offset Rail can also be used to mount a variety of lights or other accessories that mount to a MIL-STD-1913 rail. By flipping the part upside-down, one can mount a light in a good position for use with a vertical foregrip. All Daniel Defense Rails are built to the 1913 Military Specification and are 100% Quality Assurance checked for conformity to the specification.