Easily remove algae from glass or acrylic surfaces in your freshwater or saltwater tank with the Mag-Float Labs Large Glass Aquarium Scraper! It is designed with strong, high-quality neodymium rare earth magnets that do not lose strength over time. Have the privilege of keeping your hands clean and dry, even during maintenance. This Scraper remains free of debris and has simple retrieval of the inner magnet. This is suitable for aquariums up to 350 gallons and a surface thickness of up to 5/8". 3 1/4" x 2 1/2" x 1"