EnviroCare Replacement Vacuum Pre-Filters for Shark Navigator Lift-Away NV350, NV351, NV352, NV355, NV356, NV356E, NV357 Pre-Filter Kits (Containing 2 Foam and 2 Felt Filters) Washable Foam and Felt Pre-Filter Replacement Kits Fits the following Shark Navigator Lift-Away Models: NV350, NV351, NV352, NV355, NV356, NV356E, NV357 Designed & Engineered By Envirocare Technologies #F650 Absolutely Essential for Allergy Sufferers! Traps 99.97 of airborne particles Replaces: Shark Euro-Pro Part Number XFF350