【Compatible Model】This product is fully compatible with Shark Clean Lightweight Cordless Cleaner models including BU3523, BU3521, BU3120. Please confirm that your machine model matches one of our compatible products before purchasing 【Great value combo set】Keep your home clean and comfortable with our comprehensive cleaning combo set that includes 6 Auto-Empty System Pre-Motor Foam Filters and 6 Auto-Empty System Pre-Motor Felt Filters. This set can cater to your needs for up to one and a half years, offering both cost-effectiveness and convenience for all your replacement requirements 【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 【Premium Material】 The replacement pre-motor filter assembly is made of high-toughness foam and felt, specifically designed for use with your Cordless Auto-Empty System. It effectively blocks tiny particles, pollen and allergens. We aim to create a fresher and more comfortable home for those who wish to breathe fresh air. This is the right choice for you 【Easy Replacement & Installation】 No tools required for filter replacement. Simply remove and replace the filters from your Auto-Empty System equipment when needed. Quick and convenient, making your cleaning tasks smoother. If you have any questions or need assistance, we will serve you with utmost sincerity 6 Pack BU3523 BU3120 Pre-Motor Foam Felt Filter Kits compatible with Shark BU3120 Clean Lightweight Cordless Cleaner, Shark BU3523 Clean Empty Cordless Stick Vacuum, Shark Auto Empty System, XFBU3000