Milwaukee Concrete Drill Bit Set 4932471192 comes in a pack of 8 pieces. The drills are made of tungsten carbide, which allows drilling in concrete, aerated concrete blocks, masonry, slate and granite. Package contents include 5mm drill bits with 3 flat shanks to prevent slipping in the chuck. The 3 and 4 mm diameter drills are supplied with a round handle. Items feature easy identification in the user's toolbox. They can be used in rotary mode.