Milwaukee shockwave Impact Duty magnetic bit holders 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 bit holders feature a powerful magnet allowing for a secure grip and unyielding bit engagement. The 2-piece construction of the holders is the optimal assembly for abusive applications. Now use with Milwaukee shockwave impact Duty insert magnetic nut drivers (1/4 inch, 5/16 inch, 3/8 inch, 7/16 inch, 1/2 inch). Optimized Shockzone absorbs peak torque and prevents breakingPrecise and customized fitCustom alloy 76 steel maximizes resistance to wear and shockForged tips for maximum gripExtreme durabilityGeometric design provides the shock absorption zone10X longer life3 in. bit extension