CMS Magnetics 1/2x3 inch (12.7mm x 76.2mm) Neodymium Cylinder Magnet, Diametrically Magnetized with Magnetic Poles on the Sides Unbelievably Strong Holding Power, about 49 LB per Magnet. 13,500 Internal Gauss Magnetized through the Diameter. The Poles are on the 3" Curved Sides Heavy Duty Ni+Cu+Ni Triple Layer Plated - the Best Coating Available Great for Science Education and Demonstration, Science Projects and Personal Projects Made under ISO 9001 Quality System. Quality is Guaranteed. 30 Days Money Back Guaranteed