Milwaukee MX4 4-Cutter Rotary Hammer Drill Bit SDS-Plus rotary hammer drill bits provide up to 4x life in rebar and up to 20% more holes per charge in cordless rotary hammers. The enhanced rebar guards and 4-Cutter Rotary Hammer Drill Bit 90° head design provide increased life and durability in hard aggregate and rebar. Breaker point pulverize the material more effectively resulting in faster drilling speeds. The variable flute allows for maximum debris extraction leading to up 20% more holes per charge in cordless rotary hammers while making it a very durable bit in corded and cordless rotary hammers. Additionally, MX4 features a centering tip for exact spot drilling, wear mark indicator indicating when the bit no longer meets ANSI diameter requirements, and a reinforced flute for durability and minimized vibration. The increased life and efficiency of the MX4 4-Cutter Rotary Hammer Drill Bit drill bit line provides the ideal solution in general concrete and reinforced concrete for cordless and corded rotary hammer users.