Makita XT257MB 18V LXT Lithium-Ion Brushless Cordless 2-Pc. Combo Kit (4.0Ah) (Discontinued by Manufacturer) Efficient BL Brushless motor is electronically controlled to optimize battery energy use for up to 50% longer run time per charge The BL Brushless Motor eliminates carbon brushes, enabling the BL Motor to run cooler and more efficiently for longer life The 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" Hammer Driver-Drill (0-550 & 0-2,100 RPM) with BL Motor delivers 1,090 in.lbs. of Max Torque; weighs only 5.9 lbs. with battery 18V LXT Lithium-Ion 4.0Ah battery BL1840B, features an integrated L.E.D. battery charge level indicator (for TB kits)