What You Will Receive You will receive 8 S1 Spa Filters, the approximate dimensions are: outer diameter: 10.8 cm; inner diameter: 4 cm; height: 7.3 cm. Filters suitable for most swimming pools on the market. High Quality Material Our Spa Foam Filters are made of high quality sponge, which has good flexibility and high elasticity, good water permeability, strong and durable, non-toxic and odorless, safe and environmentally friendly. Premium Filtration Thanks to its high-density mesh structure, our spa foam filter can effectively filter various impurities in the swimming pool, such as leaves, grass, hair, debris, pine, insects and other floating objects. Provides you with a cleaner water environment. Cost Saving Replacing filter elements is part of daily pool maintenance. Our S1 Type Filter Sponges are easy to clean, reusable, and have a longer service life than traditional paper filter elements. Not only does this reduce your pool maintenance costs, but it also saves you a lot of time and effort. Warm Reminder The service life of the S1 Foam Spa Filter will be affected by factors such as filter performance and water temperature. In order to extend the service life of the filter element, we recommend cleaning or replacing the filter element once a week to achieve better filtration effect and keep the pool clean.