Milwaukee SHOCKWAVE Impact Duty Magnetic Drive Guides are engineered for extreme durability and up to 30x life.They feature an optimized shockzone that absorbs peak torque and prevents them from breaking. The stainless steel sleeve slides over the fastener for improved stability while the barrel has laser etched depth gauge for increased fastener control. The drive guide is magnetic to hold the fastener, while a c-ring retains the driver bit.