The Extra Hard Set, 43-piece, is a comprehensive Pick and Click set for all standard screwdriving tasks. It includes all the standard drills and sockets you need for screwing work. The screwdriver bits are made from heat-treated, S2-modified steel for hardness and wear resistance. They are color-coded to help you easily find the right bit. The set is housed in a sturdy Pick and Click case, allowing you to assemble your own toolbox and keep your bits well-organized and protected. All bits in the set have a 1/4-inch hex shank for use with three-jaw chuck drills and hex drill chucks.