M18 REDLITHIUM FORGE XC 8.0Ah Battery Pack, 18V, Delivers Same Power as HIGH OUTPUT HD12.0 in a 20% Smaller and 30% Lighter Design, COOL-CYCLE Technology for High-Speed Cooling and Less Downtime, Fast Charging Capable, Longest Life vs. REDLITHIUM Batteries, REDLINK Intelligence for Overload Protection, Compatible with All M18 Cordless Tools and Chargers.