Irwin 39109 Power Drill Installer BitsIrwin 39109 Power Drill Installer Bits Features: Constructed of premium alloy steel for boring into a variety of materials including wood, plaster, and metal lath Special 82 degree point for fast boring Wire hole at the tip of the bit makes it easy to pull wire through walls, ceilings, and floors Ideal for installation of small wire for telephones, cable, TV, computers, and security systems Diameter: 9/16" Shank Size: .370" Overall Length: 12" For installing all types of small wire in homes, offices, garages, etc Special 82º point for fast boring Hole in flute (head) makes it easy to pull wires through hole in wall Boring action is faster, smoother, cleaner in plaster, metal lath, most every material encountered in wiring installations Special flute finishing process assures quick chip removal, no clogging, no binding