Material: These fridge magnets are made of high-strength magnets and durable plastic material, so don't worry about them slipping off or loosening easily. Additionally, the round plastic cover is slightly curved and features a lightweight grip edge that holds the magnets in place. HIGH ADHESION: Magnets with 600g adhesion can hold up to 10 sheets of A4 paper, depending on the surface. The thicker and smoother the surface, the better the magnet will adhere. (Viscosity is not equal to weight representation). Good Helper: Colorful logo magnet buckle design, the magnet is not easy to fall off, durable and lightweight, cute and practical, convenient for you to use in your daily life. It can help you avoid damaging the surface of the refrigerator, prevent the refrigerator from being scratched, and is a good helper for teaching and document classification. Colorful: Package contains 50pcs round magnets in different colors. Thanks to the bright colors, you can use the magnets very flexibly and creatively. It is also very popular with elementary school students. Widely Used: Whiteboard magnets are perfect for holding notes or photos on refrigerators, lockers, cabinets, whiteboards or any other magnetic surface.