2 washable and reusable replacement Post-Motor HEPA Filters. Fits the following shark navigator lift-away models: NV351, NV352, NV350E and also the Shark Navigator Lift-Away Professional Vacuum - Models NV355, NV356, NV356E, NV357 and NV400. Manufactured by Crucial Vacuum. Fits Models: NV351 NV352 NV350E NV355 NV356 NV356E NV357 NV400 Directions for washing the post-motor HEPA Filter: 1) Remove the filter cover from the front of the vacuum by pulling up on the tab and pulling the cover away from the vacuum. 2) Take out the HEPA filter by pulling it straight out. 3) Turn the filter over so that the dirty side is on the bottom and vigorously tap it clean against a garbage can to remove any dust 4) Wash the filter under the tap using lukewarm water with the dirty side face down until the water runs clear. DO NOT put the filter in the washing machine or dishwasher 5) Allow the filter to air dry for 24 hours. Do not use a hair dryer or other heating methods to dry. 6) Once the HEPA filter is dry, replace it back into the vacuum 7) Replace the cover by inserting the two tabs into the holes at the top and then swinging the cover down until it clicks into place. Note: DO NOT operate the vacuum without ALL the filters in place. DO NOT operate the vacuum with WET filters.