Bosch 3931A-PB 120-Volt Wet/Dry Vacuum Cleaner 4 modes of operation for maximum versatility: regular, power tool, Pulse-Clean, Pulse-Clean with power tool Tank-only, plastic bag, paper bag, or slurry bag collection systems Power broker dial allocates power between vacuum cleaner and connected power tool to optimize usage Exclusive Pulse-Clean electromagnetic filter cleaning system shakes the dual filter cartridges Filters sit above maximum dust or water accumulation height to help maintain maximum airflow and suction