The Bosch SDS Plus Bulldog? Xtreme rotary hammer bit provides 4X life in concrete with rebar, due to its 100% full-carbide tip design and proprietary diffusion bonding technology. Diffusion bonding high-heat, high-pressure solid-state welding produces an incredibly strong bond. In internal tests, these bits delivered 4X life in concrete with rebar than a standard SDS Plus bit. The Bulldog? Xtreme bit provides 25% more holes per charge, with an upgraded variable flute design, four flutes transition to two flutes for fast dust removal. Its centric conical tip results in rounder holes for precision anchoring and it has a wear mark that helps to assure accuracy of the hole.