SDS-plus 2-cutter drill bits have a strong tapered core to help resist flute breaks, especially when drilling deep holes. For optimal drilling speeds, the two-stage flute design features a variable helix pattern that quickly moves debris away from the contact zone. Plus, the two sharp, carbide-cutting edges deliver clean, round holes for secure anchor installation. These bits are made in Germany and are guaranteed Tough, so tough that are offering a no back guarantee.