Makita XAG10Z 18V LXT Lithium-Ion Brushless Cordless 4-1/2" Paddle Switch Cut-Off/Angle Grinder with Electric Brake (Discontinued by Manufacturer) Electric brake stops the grinding or cut-off wheel in 2 seconds or less for maximum productivity Electronic Torque Control turns the motor off if rotation speed suddenly slows or wheel is forced to stop Automatic Speed Change technology adjusts speed and torque during operation for optimum performance The BL Brushless Motor eliminates carbon brushes, enabling the BL Motor to run cooler and more efficiently for longer life; delivers 8,500 RPM Efficient BL Brushless motor is electronically controlled to optimize battery energy use for up to 50% longer run time per charge