• Powerful Magnets: Incredible Holding Power for its Size, Grade N52 - Per Magnet Under Ideal Conditions, 7000 Internal Gauss. Stronger than N50 • Numerous Applications: Useful Magnets for Science Experiments, Classroom Magnets, School Projects, Holding, Home Improvement, DIY Projects, Speakers, Arts and Crafts and Much More Best Coating Available: Ni+Cu+Ni Triple Layer Coated. Shinny and Corrosion Resistance • Top Quality: These are the Highest Quality Magnets Made Quality Control Systems. All Tolerances are +/-0.002"