18V Cordless battery Increased run-time with 40% less weight than an 18V NiCad battery Milwaukee digital power management Temperature management extends pack life Overload current control Prevents pack and tool burn-up Cell voltage monitoring - optimizes run-time and pack- life Battery fuel gauge displays remaining run-time 2 year warranty For use with the following M18 compact tools: Ace nos. 2192334 & 2198299