Product Features: 1. This filter sponge is a filter foam that can meet most of your needs. 2. It can be cleaned and reused, which can save your cost. 3. Soft and elastic, not easy to deform and long service life. 4. The filter sponge is very suitable for freshwater and saltwater use. Soft and elastic High-density mesh structure< /h4> Good Filtering Effect Product Specification: Type: Filter Sponge Material: Sponge Color: blue Size: 10.5 * 7.5 cm Drilling size: about 4.0 cm Applicable objects: swimming pools, spas, aquariums, etc Package includes: 2 * filter sponge Reminder: 1. You can reduce the size according to your needs. 2. It is recommended to replace it once a week. 3. Due to light and screen problems, the color of the product may be slightly different from the picture.