Wet and dry pick up with variable suction control allows for the reduction of suction power if required. Constant suction power even with the finest concrete and wood dust. The filter is automatically cleaned every 15 seconds reducing filter clogging and delivering constant air flow. On/off switch to stop the automatic filter cleaning if required. Reset function automatically activates the automatic cleaning system for the next switch-on. Automatic start and stop control when the power tool is operated. The machine continues to run for an extra 15 seconds to allow all dust to be cleared from system.