Excellent Quality: The surface of the magnets is triple coated: nickel-copper-nickel. The solid metal surface protects the magnet from breakage and greatly extends its service life. Perfect Size Ø Strong Magnet: Product Size: 24pcs Ø 12 x 16mm. Each neodymium magnet holds up to 20 sheets of A4 paper on a metal surface (only 10 sheets of A4 paper on a whiteboard). Wide Use: Ideal for attaching paper, photos, cards and notes to various metal surfaces such as refrigerators, whiteboards, aluminum shelves, etc. Also suitable as a hook for hanging keys etc. [Not suitable for magnetic glass or glass magnetic boards!] Easy Grip Ø Moving: The extremely grippy conical handle makes it easy to attach or move magnets. Packed in a portable storage box to better store your magnets. Never lose a magnet! Warning: Not suitable for children under 3 years. There is a risk of suffocation from swallowing small parts. Keep away from patients with pacemakers and defibrillators!