Diablos SDS-Plus core bit extensions 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, simply 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. 4 In. (requires Diablo's core pilot bit), and 13 In. (use with Diablo's one-piece extension and pilot bit).