Jacobs 0080733 CAT V 40 ER 40 Tool Holder with 6-Inch Projection High precision: concentricity TIR &lt;= .0004-Inch at 4x D from the nose. Prebalanced at 18,000 RPM Rigidity: High alloy steel properly hardened and heat treated provides greater durability and longer life Laboratory certified for accuracy and gripping torque Through spindle coolant is standard