The MILWAUKEE® SDS Plus 4-Cutter MX4™ 1/4" X 6" X 8" Drill Bits with solid head carbide deliver up to 5X longer life in concrete with rebar. Engineered with rebar guards to provide maximum durability in hard aggregate and rebar with a 4-cutter design that prevents lock-up, reducing downtime. The sharp centering tip offers exact spot drilling in concrete and metal decking. Variable flutes remove dust faster, reducing heat and delivering up to 20% more holes per battery charge. A wear mark indicator shows end of life and when bit no longer meets the ANSI requirement. The Milwaukee MX4™ 4-Cutter Drill Bits are ideal for concrete with rebar and masonry applications.