Genuine Milwaukee HD18PD Spare Parts. Hammer mechanism delivers 28,000 BPM for highly effective masonry drilling. 24 stage torque adjustment delivers optimal control for the user. Heavy Duty 13mm full metal chuck delivers optimum bit retention. Full metal gear box delivers maximum performance and long life. 3 stage mode selector allows the user to switch between 'rotary', 'screw drive' and 'percussion' modes quickly and easily Built in LED light illuminates the work surface.