The new Bluetooth® Battery Packs communicate with the Bluetooth® module (sold separately) on the CT mobile dust extractors and ensures that even a cordless tool starts the mobile dust extractor automatically when switched on. This enables you to benefit from Festool’s entire dust-free system when working with Festool cordless products too. Long lasting, and measurably superior to other cordless tools. Now you can achieve perfect results quickly and easily with the quality you expect, even when you’re not near an electrical outlet. Festool’s Airstream Technology rapidly charges compatible batteries. Airstream technology significantly increases the battery capacity and provides faster charging. Cool air is directed through targeted air ducts in the battery and out through the charger to quickly lower the internal temperature. A minute display tells you exactly when the battery pack can be used again. This information is displayed both by the charge indicator on the charger and also by the integrated LED display on the battery pack itself.