M12 FUEL SURGE 1/4" Hex Hydr Driver Bare Tool. The M12 FUEL SURGE™ ¼” Hex Hydraulic Driver is the industries first 12V Hydraulic Driver.With Milwaukee's FLUID-DRIVE™ Hydraulic Powertrain, users will experience up to 2X quieter operation, less vibration for smoother operation and faster driving speeds compared to standard impacts.