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".