4 - FilterBuy Shark NV42 Compatible Foam & Felt Vacuum Filter Kits. Designed by FilterBuy to Replace Shark Part # XFF36. Pack of 4: FilterBuy Shark NV42 compatible filter kits. Each Kit includes all 3 foam / felt filters used on Shark NV42 Navigator Deluxe Upright Vacuum. Designed to replace Shark Part # XFF36. Each Kit includes 2 washable pre foam filters and 1 post motor filter. Premium Allergen Filter Designed by FilterBuy to fit Shark Navigator Upright models UV402 and NV42. FilterBuy: Breathe Better!