DEWALT SDS-Plus Drill Bits are suitable for fast drilling of plug, anchor or clearance holes in masonry, stone, concrete and brick/block work. The 2 flute helix has been specially developed for efficient removal of dust. There is also an optimised carbide tip drill head with 2 cutting edges. This 8 piece Set contains the following sizes:6mm (x2) , 7mm (x2) , 8mm (x2) , 10mm (x2) Specification: Overall Length: 160mmWorking Length: 92mm