Each of these extremely strong spherical magnets has a North/South orientation through its axis. This allows them to be strung into infinite chains. Toss them one at a time into a container and you can represent monomers becoming polymers. Great for experimentation; great for jewelry! Choose Gold or Silver coatings. Use different colors to represent different monomers! We can't put these down! Not for children under 3 years old. Each magnet is approximately 8mm (~0.3 inches) in diameter.Note: All Rare Earth magnets, such as neodymium magnets, are made of a ceramic and can be brittle. They are extremely strong magnetically must be handled with caution to avoid damage to the magnets and/or injury. Fingers can be pinched between attracting magnets and magnets can chip or break if allowed to 'jump' at an attracting surface or another magnet. Close adult supervision is required.