Dr. Richard Parkhouse of Wales—an outstanding clinician, speaker and author explains the design, function and advantages of a revolutionary archwire slot invented by Peter C. Kesling. It promotes tooth movement in the desired direction and creates anchorage in the other. The slot initially grows from .022 inch up to .028 inch. This eliminates binding friction, reduces anchorage strain and facilitates stepping up in archwire size. Finally the Kesling Slot closes down to .022 inch powered by a nickel titanium auxiliary to provide 100 percent of preadjusted torque and tip values.