Alternate contact points along shaft are seen in

The blank design employed by the Endo Sequence file is a triangle with alternating contact points (ACP) along the instrument's ,hunk. The Endo Sequence file undergoes electropolishing and the result is visible in its mirror-like finish that remains sharper longer and mays cleaner during use. About RACE: Design of the reamer with alternating  cutting edges (RACE): twisted areas alternate with straight parts. The NM surface is treated chemically resulting in an obviously smoother surface than other instruments. About 3: Positive rake angle Variable helical flute angle Peripheral blade relief Third radial land Variable core diameter Safe-ended tip Wide radial lands About Lightspeed: The LightSpeed root canal instrument has a noncutting tip and a short blade. The shaft is smooth, nontapered and very flexible. Instruments have physical resemblance with Gates Glidden drills. Also remember that term '12 peck e is associated with lightspeed instruments.