Features 1. Special design that aligns with the purpose of human mechanics. 2. Completely sealed with strong magnetic attraction. 3. Thoroughly cleans dirt on the aquarium glass surface. Instructions 1. Place the half with the Velcro cleaning pad inside the aquarium and align the other half with the felt pad outside the aquarium. 2. Please be cautious when handling the magnets. These magnets have very strong magnetic attraction. Keep them out of reach of children. Dimensions L - 11 × 6 × 5 cm M - 8 × 4 × 4.5 cm S - 6 × 2.5 × 4.5 cm