Makita XST01M 18V LXT Lithium-Ion Oil-Impulse Brushless 3-Speed 4.0 Ah Impact Driver Kit with LED Light (Discontinued by Manufacturer) Oil-Impulse Technology utilizes oil to hydraulically drive the impact mechanism for lower noise and increased efficiency Quick-Shift Mode selector has an automatic electronic controller that downshifts and reduces rotation and impact speed prior to driving screw The BL Brushless Motor eliminates carbon brushes, enabling the BL Motor to run cooler and more efficiently for longer life Efficient BL Brushless motor is electronically controlled to optimize battery energy use for up to 50% longer run time per charge The electronically-controlled BL Brushless Motor efficiently uses energy to match torque and RPM to the changing demands of the application