This washable and reusable replacement filter kit 2-pack by Crucial Vacuum fits the following Shark Navigator Lift-Away models: NV350, NV350A, NV350E, NV350Q, NV350T, NV350W, NV350WC, NV350WM, NV351, NV351 26, NV352, NVLFT199 and also the Shark Navigator Lift-Away Professional Vacuum - Model NV356. Replaces Shark Part# XFF350. Important: Loss of suction may occur if foam filters are not cleaned every 3 months. Rinse and allow to air dry completely. Directions for Washing the Foam and Felt Filters: 1) With the dust cup removed, pull the 2 filters out from the top of the motor base. 2) Rinse the filters thoroughly in lukewarm water until the water runs clear. 3) Squeeze out excess water and let air-fry for at least 24 hours before inserting back into the vacuum. Note: DO NOT operate the vacuum without ALL the filters in place. DO NOT operate the vacuum with WET filters. All vacuum brand and model names are registered trademarks of vacuum manufacturers.