The DCG414B 4-1/2 in. - 6 in. (115 mm - 150 mm) Grinder with Kickback Brake is maximized for power and durability. It delivers 13 Amp power as compared to the D28144N with the portability and convenience of cordless through DEWALT's revolutionary FlexVolt technology. Kickback brake engages when a pinch, stellar bind-up event is sensed and the electronic brake engages with maximum force to quickly stop the wheel, reduce the movement of the grinder, and shut the grinder off.