DEWALT DW5809-SDS Max Bit For Rotary Hammer, 5/8-Inch X 16-Inch X 21-1/2-Inch, 4-CutterSDS Max High Impact Carbide 4 Cutter Drill Bits are manufactured with IRON BLAST TECHNOLOGY, a process that strengthens the bit to resist fatigue and results in extreme durability. The redesigned, 4 cutter carbide head offers 2X longer life and even stands up to rebar strikes. If you have our bits, we have your back. Features Extreme durability: IRON BLAST TECHNOLOGYstrengthens the bit 2X longer life: Full carbide head in 4 cutter design Stands up to