Straight Shank Collet Chuck Extensions provides the undersize and oversize cutting tools is held with accuracy or gripping power. It has the universal collet which is suitable for both milling and drilling operations. It provides sixteen milled jaws for higher concentricity and high gripping power, allowing cutting tools. It is design for fewer over-hangs to prevent small cutting tool breakages. It is very useful for hard-to-reach milling and drilling operations. It design allows for the correction of misalignment between the spindle and turret centerlines. Its unique adjustable stop screw allows drill to be preset and provides through-coolant capability. It is ideal for turret and automatics.