The Dustless HEPA Wet/Dry Vacuum gives you a distinct advantage by enabling you to switch from dry to wet operation without worrying about getting the valuable HEPA filter wet. A protective baffle/wall inside the canister protects the HEPA filter from water. One of the big advantages of the Dustless HEPA Wet/Dry Vacuum is the optional Micro Pre-filter that greatly extends the life of the HEPA filter.