The Milwaukee Step Drill Bit Kit Is Perfect For Drilling Large and Small Diameter Holes In Steel and Plastic. The Bits Give You Jam-Free Performance Optimized For Cordless Drills In High Speed. The Dual-Flute Design Gives You Quicker Holes, Longer Life and More Work Time Per Battery Charge. The Rapid Strike Tips Facilitate Fast, Accurate Starts That Generate Less Heat and Give You Longer Bit Tip Life. Black Oxide Coating Also Enhances The Bits' Durability, Hole Quality and Bit Life. For Added Convenience