Crypto hardware wallet company Trezor has unveiled new wallet models and a "Keep Metal" corrosion-resistant stainless steel product for storing recovery-seed phrases.

The new Safe 3 wallet comes with a "tamper-resistant hardware component providing extra protection," according to an announcement on Wednesday.

The new Keep Metal product is used for backing up recovery seed phrases - a random string of words that the user needs to remember should they need to restore access to their wallet.

Trezor's new models come as the Prague-based firm pushes to entice more crypto users to take full control of their digital asset holdings. The company says that fewer than 2% of the estimated 420 million global crypto users use self custody at present.

The goal of the new releases is to "enable crypto novices and newcomers to enjoy the security and peace of mind that comes with owning and safeguarding their own crypto," CEO Matěj Žák said in the announcement.

The new Trezor Safe 3 wallet can be used to secure bitcoin, ether and 7,000 other coins, according to the company.

Roughly the size of a keyring with a stripped-back design and two buttons, the wallet more resembles something you'd use to open your garage door than a sophisticated piece of hardware you'd entrust with the security of your wealth of digital assets.

"The form factor and design is basically the simplicity," Žák told CoinDesk in an interview. "It doesn't pretend to be anything fancy."

The Keep Metal is a steel tube with 24 alphabet tables emblazoned onto it, on which users should punch through the relevant letters that make up their recovery seed words as an aid to memory.

Backing up seed phrases became a contentious issue in May of this year when another hardware wallet provider Ledger introduced a recovery service which would store it in encrypted fragments with third parties. The "Recover" service was not greeted warmly by the crypto community, with users claiming it undermined Ledger's brief of privacy and security.

"I understand why they did that from a business perspective, but we would never go there because it's against the principal of a hardware wallet," Žák told CoinDesk.

And in a nod to bitcoin's dominance among cryptocurrencies – and perhaps the marketing reality that some users want to store nothing on their hardware wallets beside bitcoin – Trezor has also brought out a BTC-only version of the Safe 3 wallet to celebrate the 10-year anniversary of its first bitcoin hardware wallet.

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