Made for drilling fast holes in clean wood. Double wing spurs cut clean holes for feeding wire or bolts through. Nonstick, polished and coated flutes provide fast chip removal. 1/4' power groove shank fits all 1/4' extensions. Set includes 1each, 6' long bits: 1/2' 5/8', 3/4', 7/8', 1', 1-1/4'.