Keep your Festool cordless tool running longer with this HighPower 4.0 AH Battery Pack. Integrated Li-HighPower cell technology provides optimum power for every application. Lightweight and more compact than the 5.2 AH battery, this battery pack makes all day work even easier. Bluetooth® enables a compatible CLEANTEC Mobile Dust Extractor to be started automatically when the cordless tool is activated. AIRSTREAM design allows for quicker cooling and faster recharging.