M18 18-V, 9.0Ah, Red Lithium, High Demand, 9.0 Battery Pack, Red Link Intelligence Provides Optimized Performance & Overload Protection Using Total System Communication Between Tool, Battery & Charger, Best In Class Construction Offers Long Lasting Performance & Durability, Fuel Gauge On Board Displays Remaining Run Time For Less Downtime On The Job, All-Weather Performance Delivers Fade Free Power In Extreme Jobsite Conditions, Compatible With All M18 Lithium-Ion Chargers.