[Easy Replacement and Installation]No tools are required to replace the filter.Simply remove and replace the filter from the vacuum cleaner device when needed.Quick and convenient,making your cleaning tasks smoother. [Compatible Models]This product is designed for Shark BU3523 BU3521 BU3520.Before purchasing,please confirm that your machine model matches our product. [Great Value Combo Set]Our comprehensive cleaning combo set includes 1 filter,1 filter element,1 set of filter cotton and 1 cleaning brush,ensuring that you have enough replacements to keep your device running at its best for longer,keeping your home clean and comfortable. [Washable and Reusable]Rinse the filter thoroughly with clean water,dry it thoroughly and reuse it to maximize cost-effectiveness.For optimal performance,we recommend replacing the filter set every 2-3 months to help extend the life of your vacuum cleaner. [Durable Material]The filter is made of durable material and is designed for your vacuum cleaner and automatic emptying system.It can effectively block up to 99.97% of fine dust,including tiny particles as small as 0.3 microns,pollen and allergens.Installing filter ensures optimal cleaning performance while reducing dust particles in the air,removing odors from the air,creating a healthier breathing environment,making the machine run better for a long time,and extending the life of the machine. Function: Consumables Use environment: Home use Colour:As Shown Material:Plastic + cotton Package Contents: 1 * filter screen 1 * filter element 1 * filter cotton 1 * Cleaning 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.