Bosch 21-in Masonry Drill Bit for SDS-Max DrillAccurate hole diameter ensured by placing wear mark at the tip Inclined side cutters for aggressive drilling Short head gets dust out fast and reduces heat build up Active centering tip for optimum guidance when drilling in concrete and reinforced concrete Extremely robust and aggressive solid tungsten carbide S cutters Features Series Name N A Type Rotary Bit Length 21 in Shank Size SDS max Shank Type SDS max Compatible Tool SDS max drill Set