Up to 50x more robust than a Bosch 2607001528 Extra Hard Bit. Are you looking for a compact and reliable screwdriver bit set that you can use for demanding jobs? Then the PRO Impact Set is the right choice. It contains bits that you need for many screwdriving jobs. The PRO Impact Set is a good choice for installers who are looking for robust screwdriver bits for demanding tasks. The bits are made of heat-treated, modified steel for excellent stability and resistance to high torques. Their torsion zone absorbs the torque load at the tip of the bits to ensure they do not break. They feature colour-coded rings to indicate the head type and laser markings to help you select the size you need. They are housed in a sturdy case and arranged in holders that allow you to assemble your own toolbox. Impact-resistant 1/4 inch hexagonal shank for use with impact wrenches and drill drivers.