25 PIECE SET. 1.00MM-13MMx 0.5MM INCREMENTS..SURFACE TREATED,? HIGH SPEED STEEL, JOBBER LENGTH DRILL BITS.A DEPENDABLE GENERAL PURPOSE DRILL? BIT DESIGNED TO PERFORM IN A BROAD RANGE OF MATERIALS IN THE IRON AND STEEL FAMILIES. IDEAL FOR PRODUCTION, MAINTENENCE OR PORTABLE DRILLING JOBS.