The Mag-Float-410 Large Acrylic Aquarium Cleaner is recommended for use with acrylic aquariums up to 400 gallons with a surface thickness up to 3/4". Product dimensions: (6" x 2-1/2" x 1").The Mag-Float cleaners contain special abrasive velcro pads that remove algae from the surface of your aquarium. You can use the Mag-Float Lg & Lg+ Feeding Clip with this cleaner. Includes one Mag-Float Acrylic Scraper. The Mag-Float floats when the inner magnet separates from the outer magnet. Because you never have to reach into the aquarium, not only can you stay clean and dry, but you also avoid toxic lotions or soap residue on your skin from getting into your aquarium water. Can be used on freshwater and saltwater tanks. Magnet does not lose strength over time.