Milwaukee® SHOCKWAVE™ Impact Duty™ magnetic bit tip 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. Nw use with Milwaukee® SHOCKWAVE™ Impact Duty™ insert magnetic nut drivers (1/4 in., 5/16 in., 3/8 in., 7/16 in., 1/2 in.).