【Strong Magnet】: This aquarium magnetic glass cleaner, built-in double magnet. As you move this magnetic aquarium brush, when you move the small outer aquarium brush, the magnetic brush inside follows: Quickly and easily cleans away algae growth to keep your aquarium healthy and looking its best. Non-slip handle: Improved soft grip is contoured, non-slip, comfortable, saves time and money. Note: Not suitable for acrylic aquariums and low iron glass aquariums 【Removes algae and does not harm glass】: The side of the scrubbing handle is covered with felt so it glides easily when you move it, the other side is made of fabric with tiny hooks that scrape up algae without damaging the glass. Floating design: the inner brush won’t sink in in the outermost depths of the aquarium. Convenient to use. Size: M (10.5 x 4.8 x 7.5cm), glass thickness (less than 6mm)