The Milwaukee Locking Bit Holders are engineered to be the most durable, strongest locking bit holders on the market. The intuitive auto-locking design fits all inserts and 1/4" hex bits and the small-profile quick release collar allows for easy one-handed bit tip changes. The MILWAUKEE® SHOCKWAVE™ Impact Duty™ locking bit holders feature two magnets to maximize magnetic transfer and holding power to the fastener and prevents drops. Each Milwaukee bit holder features an optimized Shockzone™ geometry to provide up to 30x longer life and absorb 3x more torque to prevent breakage.