Diablo's pilot bit for SDS-Plus core bits attach to thin wall carbide tipped core bits to provide one of the fastest and longest lasting coring solutions on the market for concrete applications. To use, attach pilot bit to the extension and then simple screw the core bit onto the extension. Optimized with a unique brazing and hardening process, Diablo's thin wall carbide tipped core bits extend life and productivity, allowing users to drill fast, clean holes. Optimized for maximum performance in corded and cordless SDS-Plus rotary hammers.