Model DCG412B. 20V MAX Li-Ion 4-1/2 in. Grinder (Tool Only) - DCG412B. Dewalt 20V MAX Brushed Lithium-Ion 4-1/2 in. Cordless Grinder (Tool Only). Power Source Cordless. Battery System 20V MAX. Quick-change wheel release allows for tool free wheel changes without the need for a wrench.