【Strong Magnet】: This magnetic aquarium cleaner has a built-in double magnet. When you move this magnetic aquarium brush, when you move the small outer brush of the aquarium, the magnetic brush will interior follows: Quickly and easily cleans up 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 Won’t Damage 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 which scratch the algae without damage the glass. 【Floating Design】: This magnetic glass cleaner inside the brush won’t sink to the farthest depths of the aquarium. Convenient to use. Size: S (8 x 3.6 x 5.7cm) glass thickness (less than 4mm)