The SMBN0488 block neodymium magnet is made from high performance N42 NdFeB, with Nickel coating. The dimension of this item is 3/4″ length × 3/4″ width × 3/8″ thick, with step IN, magnetized through thickness, with the tolerance of ±0.004″ × ±0.004″ × ±0.004″. The weight of this super strong neodymium magnet is 0.054 lbs. It can pull up to 28.38 lbs steel. And the surface field is up to 4537 gausses.