The Hitachi 724981 SDS MAX 13/16-Inch by 17-Inch by 21-Inch Cutter Drill Bit Set withstands months of repeated use and does not wear or break. The Special Direct System offers a number of advantages over drill chuck systems, including improved hammer action and the option to move bits forward and backward within the chuck. These carbide tipped bits have a chisel shape design for optimal performance. Carbide gives saw blades and some router bits a sharper, longer lasting tip. This product is stronger than conventional steel drill bits. with an overall 17-Inch drilling depth and 21-Inch length, this product is designed to conquer all your home improvement and remodeling needs. This Special Direct System drill bit fits most drills and stays in place for heavy-duty applications. These bits are strong and will not slip or slide, and come in a convenient 4-Piece set. Always have a bit nearby with this drill bit set. This product is perfect for drilling holes in a variety of materials and features a multi-fluted spiral and patented core reinforcement. The Hitachi 724981 SDS MAX 13/16-Inch by 17-Inch by 21-Inch Cutter Drill Bit Set is warranted to the original purchaser to be free from defect in materials and workmanship for a period of 30-days from the original purchase date. Every Hitachi accessory is designed to the highest standards and is rigorously tested for both performance and durability. Since its inception, Hitachi has pioneered innovative technologies that have improved the quality of craftsmanship worldwide. Hitachi is a leader in power tool research and development and has achieved many firsts in the power tool industry. Today, Hitachi continues the tradition of innovation and engineering with new features in addition to classic quality.