Makita XT269T 18V LXT Lithium-Ion Brushless Cordless 2 Pc. Combo Kit, XPH12Z, XDT13Z, bag (5.0Ah) with XAG04Z 18-Volt LXT Lithium-Ion Brushless Cordless 4-1/2 / 5 in. Cut-Off/Angle Grinder

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
Automatic speed change technology adjusts speed and torque during operation for optimum performance
Active feedback sensing technology (aft) turns the motor off if rotation of the wheel is suddenly forced to stop
The BL Brushless motor eliminates carbon brushes, enabling the BL motor to run cooler and more efficiently for longer life