The Cryptosteel is a device made entirely from German stainless steel, specifically designed to store seed keys of any deterministic crypto hardware wallet (such as Trezor, Ledger, etc.) in an indestructible and fire & waterproof manner. Thanks to the Cryptosteel you have the complete assurance that your seed key will never get destroyed.
The device has two separate sides, each capable of holding 12 words of maximum 4 letters each (see Step 6 below), which is enough to store the entire seed key of any deterministic crypto hardware wallet (such as, the Trezor hardware wallets and the Ledger hardware wallets).
Start out by using the steel letter tiles, which are included in the box, to assemble your seed key. Then you can start inserting the steel letter tiles, in the correct order, into the Cryptosteel device. Make sure to follow the below step-by-step instructions.