Two Little Fishies NanoMag is an itsy-bitsy, lean, high-energy, window-cleaning apparatus. Its patented design provides flexibility and a slender profile that slips safely between polyps or plants and viewing windows. It's got the umph needed for cleaning glass up to 1/2-Inch thick. The NanoMag also glides across the curved surfaces of fish bowls, wiping off algal films with ease and it's so much fun to use you just might have to take turns.