The material, steel, was carefully selected to provide an indestructible physical backup tool for the user's recovery seed. It is resistant to fire, water and even to corrosion. Its sturdiness also protects the seed from physical damage.
How to use Cryptosteel
Cryptosteel comes with more than 250 stainless steel letter tiles engraved on each side. You can assemble your recovery seed manually from the supplied set of tiles.
Cryptosteel has space for 96 characters. If your recovery seed is longer, do not worry. For each recovery seed word, assemble only its first four letters. The BIP39 format ensures that seed words are designed so that they can have no more than the first three letters in common. First four letters of each word are, therefore, sufficient to ensure that your backup is unique.