These giant cubes are not for the neodymium amateur or for most experienced handlers for that matter. They are VERY strong and can pinch VERY hard if mishandled. Only purchase these cubes if you know what you are doing and have a specific purpose in mind. They will hold a lot of weight and can be incredibly useful, but must be handled properly.
This size is also available in grade N52 as part number BX0X0X0-N52