DeWalt's Extreme series have the been introduced into the Stanley Black and Decker family using all the features of the Irwin Blue Groove bits with the added benefit of being impact rated with 1/4" hex shanks, making them suitable for use in impact drivers as well as all standard drills with a jawed chuck. The DeWalt EXTREME® Tri Flute Bit 3 Piece Set is designed with 3 cutting edges to allow for up to 6x faster cutting, combined with tri-flute design for optimum chip removal. The 3 cutting spurs allow for cleaner, faster holes and extended drilling life, The full screw tip allows the bit to self-feed for ease of use and pull through. The quick-change shank fits standard Quick-Change extensions and 1/4" / 6mm hex bit adaptors and also prevents spinning. Sizes: 16, 20 .