Petluno Magnetic Aquarium Glass Cleaner Fish Tank Glass Algae Scrapers, Floating Scrubber Cleaning Brush, Scratch-Free, Anti-Slip with Handle (M) M: suggests

【HANDLE DESIGN GREEN SLIP】: The improved soft handle is streamlined, non-slip, comfortable, labor-saving and time-saving. Note: NOT suitable for acrylic aquariums and glass aquariums with low iron content 【STRONG MAGNET】: This magnetic aquarium glass cleaner features a built-in double magnet. When you move this magnetic aquarium brush, as you move the small brush of the external aquarium glass cleaner, the internal powerful magnetic brush follows, quickly and easily cleaning algae, keeping your aquarium healthy and looking its best. 【REMOVE ALGAE AND NO GLASS DAMAGE】: The side of the scrubber handle is covered with felt, so it glides easily when you move it; the other side is made of fabric with small hooks that scrape off algae without damaging the glass. 【Floating design】: the inner brush doesn't sink to the deepest parts of the aquarium. Easy to use.