The extension sleeve is used to lengthen Morse taper tools to allow work in hard-to-reach places. For example, Morse taper drills can be lengthened to work in deeper holes. The extension also minimizes direct load on the spindle, reducing wear and damage.
 
The sleeves have a Morse taper shank both on the outside and inside. The flat shank (ejection shank) makes it easy to remove the sleeves from the machine.
Made of hardened and ground steel