System accessory GCT 30-42. When working with a vacuum cleaner, you typically need to operate both your tool and the vacuum. That’s why we developed Auto-Start, to wirelessly synchronize battery-operated devices and vacuums so they automatically start and stop at the same time. The Auto-Start module GCT 30-42 Professional can be easily attached to many battery-operated devices using the three included rubber bands. Quickly pair the GCT 30-42 Professional with an external Auto-Start plug or a connected vacuum with just the push of a button. And you're ready to go! The Auto-Start module detects vibrations from the running tool and automatically turns the vacuum on and off for you. This allows you to fully concentrate on your work. Auto-Start manages your vacuum while you focus on drilling, chiseling, cutting, or sanding. You can use Auto-Start anywhere you need a battery-operated device in combination with a vacuum. Includes 3 flexible rubber bands and 1 x 3 V CR2032 lithium button cell battery.