Never fail magnetic cleaner; SMALL. Good absorb ability and powerful magnetic attraction. As you move the outer magnet, the inside magnet follows,hence cleans the glass. The inside brush will not sink into the farthest depths of fish tank as it is floating. Super strong magnets for use with varying glass thicknesses. Floats avoiding lost magnets on the bottom of your aquarium. Anti Scratch cleaning pads that are highly efficient in removing algae from glass. Non slip griped handle improving cleaning action. 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. Simply drag the no-scratch, felt-lined handle and inside your aquarium, the scrubber follows, cleaning as it goes.