The SMCN0311 cylinder neodymium magnet is made from high-performance N42 NdFeB, with Nickel coating. The dimension of this item is 1/4″ dia. × 7/8″ thick, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.011625 lbs. It can pull up to 4.09 lbs steel. And the surface field is up to 6534 gausses.