The SMBN0444 block neodymium magnet is made from high-performance N42 NdFeB, with Nickel coating. The dimension of this item is 1/2″ × 1/2″ × 1/8″ thick, magnetized through thickness, with a tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.0085 lbs. It can pull up to 7.34 lbs steel. And the surface field is up to 2704 gauss.