Milwaukee Individual SwitchBlade Self Feed BitsSpeed: Aggressive Feed Screw Design Allows the Bit to Pull Through the Wood Faster and without Effort, Resulting in Faster DrillingReplaceable SWITCHBLADE: The SWITCHBLADE Replaceable Blade System Ensures your Blade is Always Razor SharpIt Increases Productivity by Eliminating Resharpening Downtime and it Increases the Overall Life of the BitApplication: Suitable for all General Contractors, Electricians, Plumbers and Engineers who Require to Drill through Holes in Wood for all Types of Pipe, Vents and Wire TrunkingEach Self Feed Bit is Supplied with 2 x Blades, 2 x Replaceable Feed Screws, 2 x Set Screws and 1 x Allen KeyAvailable in the Following Sizes: 35mm 38mm 51mm 54mm 57mm 65mm Shank Diameter: 7/16" Hex Shank