SHOCKWAVE™ Impact Duty™ Magnetic bit holders are engineered for extreme durability and up to 30X life. The Milwaukee® Magnetic bit holders are made from proprietary steel, heat treated to control hardness. The SHOCKWAVE™ magnetic bit holders feature a powerful magnet, providing you with a secure grip and unyielding bit engagement. Each bit holder has a 2-piece construction for optimal assembly in abusive applications. Our SHOCKWAVE™ Impact Duty™ magnetic bit holders have a C-ring to retain the insert bit and can now be used with Milwaukee® SHOCKWAVE™impact duty insert magnetic nut drivers.