[Refrigerator Magnets] These powerful black magnets measure 12*16 mm. Despite their small size, they have a strong magnetic force. You don't have to worry about magnet issues; they work perfectly. Each pack contains 30 magnets. [High-Quality Materials] The powerful magnets consist of a metal shell and super strong neodymium magnets. A three-layer coating ensures rust and corrosion resistance, a smooth surface, durability, and a long lifespan. These mini magnets will not lose their magnetism over time. [Powerful Functions] The main function of refrigerator magnets is to attract paper, photos, or hang small items. They easily attach to magnetic surfaces such as refrigerators, whiteboards, or other metal surfaces. [Wide Range of Applications] Refrigerator magnets are very practical small tools, easy to use and portable, suitable for a variety of purposes. No glue or other fasteners are needed, and they leave no residue or stains after application. Examples include refrigerators, magnetic whiteboards, bulletin boards, iron doors, iron frames, and office areas.