MILWAUKEE® MX4™ 4-Cutter SDS Max Rotary Hammer-Drill Bits with solid head carbide deliver up to 5x longer life in concrete with rebar. Rebar guards provide maximum durability in hard aggregate and rebar. Sharp centering tip for exact spot drilling in concrete. Integrated 4-cutter design prevents lock-up in rebar, reducing downtime. Variable flutes removes dust faster for up to 15% more holes per battery charge. This bit features wear mark indicators to show end of life and when bit no longer meets the ANSI requirement. Ideal for concrete with rebar and masonry applications.