Zxlight&reg;new Magnetic Aquarium Fish Tank Glass Algae Scraper Cleaner Floating Clean Brush Clean algae and scum off of the inside of your aquarium the easy, fun way! Strong magnetic forces cause the inside cleaning brush to follow the outside handle. Just wipe the outside, and the inside is cleaned! The inside piece floats, so if it becomes separated from the outside piece, it's easy to retrieve. this product comes with a 2-year warranty and 100% money-back guarantee.