Tired of sticking your whole arm into the tank to clean the glass? A Neptonion magnetic glass cleaner is just what you need.\r\n Begin by giving the glass a good cleaning on the inside with an Magnetic Algae Cleaner. This is pretty straight forward, scrub until all the algae is gone.\r\n These devices help clean glass by magnetizing from an outside pad to the inner glass cleaner part.\r\n This makes cleaning your glass much easier by eliminating the need to need to place your arm in water when cleaning the tank, which could cause issues with the quality of your water.\r\n\r\n????About Sizes:\r\n This magnetic cleaner from Neptonion is meant for glass tanks and comes in a few different sizes. When choosing a size, remember that the larger the cleaner, the stronger the magnet.\r\n\r\n????Measurement：\r\n ????\r\nS: approx.\r\n7x 3.8 x 6 cm or\r\n2.8 x 1.5 x 2.4 inch (Suitable for 0.5cm/0.2in glass)\r\n ????\r\nL: approx.\r\n10.8 x 5.9 x 9cm or\r\n4.26 x 2.33 x 3.55 inch (Suitable for 1.2cm/0.48in glass)\r\n ????\r\nXL：approx.\r\n12.3 x 6.5 x 10.5cm or\r\n 4.84 x 2.56 x 4.14inch (Suitable for 1.5cm/0.6in glass)\r\n\r\n????IMPORTANT: Made for common glass fish tank.\r\n Not for acrylic and low iron glass. Please choose the size by the thickness of your fish tank glass.\r\nTHE LARGER,THE STRONGER MAGNET. \r\n\r\n????Notice:\r\n ►This product is not suitable for those who installed a pacemaker as its strong magnetic force, and 10-year-old children as well, to protect hands from pinch.\r\n ►When the scraper arrive the bottom of fish tank, be careful not to carry with sand to avoid scratching the glass.\r\n ►Please keep the algae scraper away from the high temperature place, as you know high temperature will eliminate the magnetism.\r\n ►Please stay away from all kinds of fear of magnetic products, like monitors, televisions, watches, magnetic cards, etc.