Aquarium Glass Cleaner Brush with Algae Magnet for Fish Tanks Cleaning - XLFeature Good holding power and strong magnetic attraction. As you move the outer magnet, the inner magnet follows, cleaning the glass. The inner brush will not sink to the bottom of the aquarium as it floats. Super strong magnets for use with varying glass thicknesses. Floats avoid lost magnets on the bottom of your aquarium. Anti Scratch cleaning pads that are highly efficient in removing algae from glass. Nonslip griped handle improving cleaning