The DeWalt SDS Rotary Hammer blasts holes up to 7/8-inch in diameter through dense rock, solid concrete, and virtually any other masonry material with lightning speed and surprising ease. This ultra-heavy duty, 18V tool produces an impressive 1.7 ft. lbs. of impact energy, resulting in corded power without the cord. Its high-performance, commercial-grade motor drives the bit at 01,100 RPM and 04,100 BPM, while the variable speed, reversing switch provides precise control throughout use. And the electro-pneumatic hammer mechanism ensures fast penetration with very low vibration.