for for SHARK Cordless Models: Specifically designed for for SHARK Clean Lightweight Cordless Cleaner models BU3523, BU3521, and BU3120, these replacement provide a secure fit to insure optimal vacuum performance and suction power. Complete 9-Piece Filter Kit: This value set includes 2 Handheld Vacuum Pre-Motor , 2 Auto-Empty System Pre-Motor Foam , 2 Pre-Motor Felt , 2 Post-Motor , and 1 cleaning brush for comprehensive maintenance of your cordless vacuum system. Washable & Reusable Design: Crafted for long lasting use, these can be easily rinsed and air-dried, allowing for multiple uses. Replace every 2-3 months to maintain peak filtration efficiency and reduce long-term cleaning costs. Advanced Filtration Performance: Constructed with high-toughness filter paper, this replacement filter captures up to 99.97% of microscopic particles as small as 0.3 microns, helping forestall recirculation for a fresher home environment. Tool-Installation: Designed for convenience, these require no tools for replacement. Simply remove the old and snap the new ones into place, making vacuum maintenance quick and hassle-.