This industrial 75 piece quality tool set of special chrome-molybdenum-silicon-manganese-vanadium steel alloy has virtually all types of specialist bits for the modern engineering and mechanical world today, including a screwdriver with positive spring-sleeve holder for bits. It also includes a magnetic holder for work with electric screwdriver or drill, an adaptor with male square and male hex drive and matching attachment with female square and female hex drive, and a special attachment for centrically clamping screw hooks and similar parts. All in sturdy steel box with durable powder coated finish. Each part is clearly marked and has a fixed location within the box - see instantly when one has been borrowed!