The Milwaukee 64 pc. Standard driver bit set features premium-grade S2 tool steel driver bits that have a durable composition giving the user longer bit life. This set also includes magnetic nut drivers for fast, easy driving of nuts, bolts and other hexagonal type screws. Additionally, the magnetic drive guide included in the kit helps reduce slipping and wobble by holding long fasteners in place while the sleeve retracts as the screw is driven into the material. This 64 pc. kit has multiple quantities of the most commonly used sizes for heavy-duty users.