1/2" x 16" x 18" Rock Carbide SDS+ Hammer Bit The DeWalt 1/2" x 16" x 18" rock carbide SDS+ hammer bit is an extremely durable and useful attachment. Use this to increase your efficiency and decrease your work time. Superior build quality means you will be using this bit for years with minimal wear and tear. A must have for any professional or do-it-yourselfer. Features: ROCK CARBIDE Tip for Longer Bit Life Elongated Four Flute Helix for Faster Material Removal Increased Steel Prevents Breakage Specifications: Diameter: 1/2" Usable Length: 16" Overall Length: 18" DEWALT is firmly committed to being the best in the business, and this commitment to being number one extends to everything they do, from product design and engineering to manufacturing and service.