These mighty blocks are definitely not toys. These things are very strong and will pinch if mishandled. They have an incredible amount of holding power and are a great choice for more demanding applications. Only purchase these if you are familiar with handling larger neodymium magnets and can do so safely.
These blocks are often used for water conditioning and making fuel saving devices.
Also available in this size: BX0X06TP-N52
(Grade N52, Black rubber coated) and BX0X06
(Grade N42, Nickel Plated)