Makita XAG06Z 18V LXT Lithium-Ion Brushless Cordless 4-1/2" Paddle Switch Cut-Off/Angle Grinder Kit 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 The electronically-controlled BL Brushless Motor efficiently uses energy to match torque and RPM to the changing demands of the application Compact and ergonomic design at only 14-1/4" long