The Milwaukee SHOCKWAVE Locking Bit Holder is made from custom engineered steel and heat-treated for maximum strength and flexibility. It features auto-locking, one-handed bit release. The optimised SHOCK ZONE absorbs up to 3x more torque, providing resistance to shock from impacting. Dual internal magnets ensure magnetism to fasteners, making it suitable for high torque and impact applications. It has a 1/4in Hex reception (DIN 3126 - E 6.3).