[Compatible Model] This product is fully compatible with for Shark Clean Lightweight Cordless Cleaner models including BU3523, BU3521, BU3120. Please confirm that your machine model matches one of our compatible products before purchasing. [Washable & Reusable] Maximize cost-efficiency by rinsing our filters thoroughly with clean water, allowing them to dry thoroughly, and reusing them. For peak performance, we recommend replacing the filter set every 2-3 months to help extend the lifespan of your vacuum cleaner. [Easy Replacement & Installation] No tools required for filter replacement. Simply remove and replace the filters from your vacuum cleaner equipment when needed. Quick and convenient, making your cleaning tasks smoother. Please note:the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:As Shown Material:Plastic Package Contents: 2 * hand-held vacuum motor pre-filters 4 sets * automatic emptying system motor prefilter assemblies (4 foam filters and 4 felt filters) 2 * automatic emptying system HEPA filters 1 * clean brush Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.