18V LXT Lithium-Ion Brushless Cordless Combo Kit 5.0 Ah (2-Piece) Variable 2-speed hammer driver-drill with Makita built BL brushless motor delivers (0 RPM - 550 and 0 RPM - 2,100 RPM) and 1,250 in./lbs. of peak torque, weights only 6.0 lbs. with battery Impact driver features 4-speed power selection (0 RPM - 1,100 RPM/0 RPM - 2,100 RPM/0 RPM - 3,200 RPM/0 RPM - 3,600 RPM and 0 IPM - 1,100 IPM/0 IPM - 2,600 IPM/0 IPM - 3,600 IPM/0 IPM - 3,800 IPM) provides 1,600 in./lbs. of max torque, weighs only 3.4 lbs. with battery Efficient BL brushless motor is electronically controlled to optimize battery energy use for up to 50% longer run time per charge Electronically-controlled BL brushless motor efficiently uses energy to match torque and RPM to the changing demands of the application I used only one year