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 ; Features 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, 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