Our 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 (¼, 5/16, ?, 7/16, ½).