These Interpet Algae Cleaning Magnets are an easy solution to effectively remove algae from inside of the aquarium walls. They use a magnetic attachment for easy algae removal without wet hands or disturbing fish. Specially designed to effectively remove algae and grime from glass or acrylic aquarium surfaces. Perfect for small aquariums, providing efficient cleaning in tight spaces. Built with high-quality materials for long-lasting performance and reliability. Suitable for aquariums up to 200 litres or thickness up to 9.5mm.