Aquarium Magnetic Glass Cleaner (medium) for Scrub Control Manage 15 ~ 50gal fish tank Algae &ndash; Around Adult Fist Size Aquatic Floating Brush Clean algae and scum off of the inside of your aquarium the easy, fun way! Simply drag the no-scratch, felt-lined handle and inside your aquarium, the scrubber follows, cleaning as it goes The Magnetic Cleaner can handle for 0.55-0.79 thickness of glass. It is suitable for many aquarium tanks, like freshwater tanks, saltwater tanks and grass tank The inside brush will not sink into the farthest depths of fish tank as it is floating, the inside piece floats, so if it becomes separated from the outside piece, it's easy to retrieve Around adult fist size, Suitable small to medium aquariums Note: Please choose by the thickness of your fish tank glass and not put the cleaner into seawater for a long time to avoid being corroded when not in use