The ST 11 is a lathe boring tool designed to fit in the boring tool holder of your Shopmaster machine. It is 6" long and made of high speed steel and utilizes replaceable carbide triangular tips. One tip is included with the unit and extra tips are available under the part # ST 11A. A plastic holder and allen tool are also included. Use the ST 11 when boring parts such as cylinders held in your lathe chuck.