3 Piece SetDrives: 1/4", 3/8" And 1/2"Overall Length: 1-7/8"Shank: 1/4" Hex Power GrooveUse With Sockets For Fast, Easy Driving Of Nuts, Bolts And Hex Head ScrewsAdds Versatility To Any Power Drill By Converting It To A Socket DriverMade From Proprietary Steel And Heat Treated To Control HardnessDesigned To Withstand The High Torque Of Impact Drivers