【STRONG MAGNET 】:this fish tank cleaner magnetic,built-in dual magnet.When you move this magnetic fish tank brush,As you move the outer aquarium glass cleaner small brush, the inside power magnet brush follows,quickly and easily cleans away algae growth to make your aquarium stays healthy and looks its best. 【HANDLE DESIGN NONE SLIP】:The upgraded Soft handle is streamlined, anti-slippery, comfortable, labor-saving and time saving. Note: NOT suitable for Acrylic fish tank and low iron glass fish tank 【 REMOVE ALGAE AND NOT HURT GLASS 】: The scrubber handle side covered in felt so it glides easily when you move it,the other side is made of fabric with tiny hooks that scrape off the algae without damaging the glass. 【Floating design】: This magnetic fish tank glass cleaner inside brush will not sink into the farthest depths of fish tank. Convenient to use. size:S(3.141.412.26inch) glass thickness(less than 4mm)