The DEWALT 7/8 In. x 16 In. x 21-1/2 In. 4 cutter SDS max rotary hammer bit has been tested on real world jobsites to ensure that it holds up and performs well under tough conditions. The rock carbide tip maximizes carbide surface contact, and a hardened core reduces breakage, so you can work confidently knowing that this hammer bit is built to last. With a U-flute design that cleans out debris and an open head to channel dust into the flutes, drilling is fast, clean, and efficient even on repetitive drilling jobs. With tools that meet your standards, DEWALT has your back.