1. Strong magnets are used to control the inner cleaning brush to follow the outer handle, so that the inner side can be cleaned while wiping the outer side. 2. The inner floating design prevents the brush (the part inside the water tank) from sinking to the bottom of the aquarium, making it easy to remove from the aquarium. 3. Soft bristles can quickly and effectively clean the internal parts without scratching the aquarium glass. 4. It comes with an algae scraper, which is easy to install and can effectively and easily scrape away algae while cleaning the fish tank. 5. Made of plastic, it is durable and corrosion-resistant. 3 sizes are available for you to choose from to meet your different needs.