From the Manufacturer

Milwaukee Shockwave Impact Duty Magnetic Nut Drivers are engineered for extreme durability and up to 10x life. Made from proprietary steel and heat treated to control hardness, the Shockwave Impact Duty Magnetic Nut Drivers feature a powerful magnet allowing for a secure grip and unyielding bit engagement. The bits feature color-coded rings for quick and easy size identification and a chamfered edge to allow for fastening in tight spaces. Broadly targeting cordless users, the Shockwave Impact Duty accessory line is not only ideal for heavy duty impact applications, but delivers a full system solution for all the user's drilling and fastening needs. Proprietary steel and heat treat process for maximum strength and durability. Strong magentic tip for secure grip. Color-coded band for easy size identification. Chamfered edge for fastening in tight spaces.