Makita XT281S Lithium-ion Brushless Cordless 2-Piece Combo Kit, 18-VoltHighlights: Battery Power Type : Lithium Ion Efficient BL brushless motor is electronically controlled to optimize battery energy use for up to 50% longer run time per charge BL brushless motor eliminates carbon brushes, enabling the BL motor to run cooler and more efficiently for longer life Electronically controlled BL brushless motor efficiently uses energy to match torque and RPM to the changing demands of the application Variable 2 speed 1 2 in.