As water enters the ProFlex, it flows through a revolutionary bubble diffuser chamber where bubbles are expelled, significantly reducing noise. After water flows through the bubble chamber, it flows through two 200 micron filter socks to remove large particulates. This easy to install bag is sock-style with a cylindrical-base and it's machine washable for unlimited uses. Replacement Filter Bags to be used on all ProFlex Modular Sump Filtration Models. Developed by true aquatic hobbyists, Aqueon provides a broad array of aquarium solutions to help maintain healthy, life-sustaining aquatic environments. Because with the Aqueon brand, it's all about the fish.