The Milwaukee M12 Xc 4.0Ah Battery 2-Pack is compatible with all Milwaukee M12 cordless tools and instruments. The M12 Redlithium Xc extended-capacity battery delivers 4Ah (48 watt-hours) of runtime, even in sub-zero temperatures. Each 12-volt lithium-ion battery features new-age Redlink circuitry engineered to prevent overloads and protect against cell-damaging discharge. Revolutionary cell monitoring and temperature regulation prolong this battery's operation and life expectancy, meaning fewer work interruptions and more recharges than ever. Professionals depend on heavy-duty, long-lasting performance, which Milwaukee delivers with this 12-volt battery pack.