The vacuum levels range from 0 to 3. Level 0 produces only enough vacuum to close the chamber. This is suitable for packaging items you want to treat delicately, such as potato chips, popcorn, or berries, or if you want to seal the bag leaving air inside. Vacuum level 3 is recommended for preparation techniques that require total air removal, such as speed marinating. Level 3 should be used only when the food will not be negatively affected by the compression.