Features: The streamlined designs are beautiful and pleasing to the eye. The floating design avoids the loss of magnets- at the bottom of the fish-tank and easy to use. Anti-skid handle improves cleaning action. Suitable for 4-8mm thick glass aquarium. The anti-scratch cleaning pad removes algae efficiently. Strong magnetic force, stable and waterproof. No damage to the glass. Specifications: Material: Magnet+Plastic Size: Approx.2.9x2.9cm/1.14x1.14inch Package Includes: 1x Algae Scraper note: 1. Avoid quick collision- when using, be careful to pinch- hands- and hurt the glass. 2. Do not put this product near electronic devices, watches, magnetic cards, medical- equipment, etc. with strong magnetic field (pacemaker- and heart stent- installation is prohibited-). 3. Limited to aquarium use, do not let children touch--. 4. Do not recommend the use of acrylic aquarium, avoid the sand and other hard particles between the aquarium and the glass. 5.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 6.Due to the differences between different monitors, the picture may not reflect the actual color of the item.