ONE lot of 20 Magnets. Size: 1/4 inch diameter x 1/4 inch thick cylinders Nickel (Ni) Plated (silver-like shine) Grade: N48 - Extremely powerful magnetic material Pull Force is approximately 6.1 pounds under ideal conditions. These cylinders are axially magnetized, so the strong North/South poles are in the center of the flat sides. That makes them easier to stack into a cylinder than to connect side by side. The metal coating is durable, but ALL Neodymium magnets can chip or shatter. If used gently, these magnets can serve you for a lifetime.