The Milwaukee M18B9 18v 9.0Ah Li-ion High Demand Battery Pack is made for high demands: - M18 FUELTM products with high power consumption (saws, circular angle grinders, mitre saws, hammers, saws etc.) - Long stamina - Replacement Wired machines or devices greater Volt classes. This battery is ideal for use by any professional tradesman that has any M18 Milwaukee power tools. It provides 15% more power and produces twice the amount of work that a 5.0ah battery does. The durable metal frame construction with built-in shock responsive separators prevents battery failure from excessive vibrations or drops, ensuring this battery is more robust and durable than most.