Dymax Mag-Scraper is a float type magnet scrap and scrub device that makes aquarium maintenance easier and quicker without submerging hands into water. This product is made of strong and reliable material which is suitable for both freshwater and marine aquarium use. The Mag-Scraper includes two attachable plastic scraper blades that help remove stubborn algae or debris off the glass surface. Suitable for glass thickness 4-8mm. DM451