Dewalt D21570K 1300w 127mm Diamond Drill The Dewalt D21570K diamond drill has a new top of the range motor which provides improved performance in applications with dry core bits up to 127mm in bricks or soft masonry. It has a two-speed gearbox for increased versatility when drilling in wood, metal and concrete with standard drill bits and a heavy-duty 16mm steel chuck for quick bit change and excellent bit retention. Features: - The new motor gives improved performance in applications with dry core bits up to 127mmn in bricks or soft masonry - Electronics provide e-clutch, power-up and overload protection - Two-speed gearbox for increased versatility when drilling in wood, metal and concrete with standard drill bits - Electro-Mechanical clutch increases user control and.