Makita 18V LXT Lithium-Ion 4-Pc. Combo Kit (5.0Ah) Efficient BLT Brushless motor is electronically controlled to optimize battery energy use for up to 50% longer run time per charge The BLT Brushless Motor eliminates carbon brushes, enabling the BLT Motor to run cooler and more efficiently for longer life The electronically-controlled BLT Brushless Motor efficiently uses energy to match torque and RPM to the changing demands of the application Variable 2-speed 1/2″ Hammer Driver-Drill (0-500 0-2,000 RPM) (0-7,500 0-30,000 BPM) delivers 530 in.lbs. of Max Torque weighs only 4.0 lbs. with battery