Do you remember Cryptosteel, well there seems to be some competition in the undestructable steel private key backup space with Billfodl. It is another steel crypto wallet that offers extreme protection and safety for your secure crypto wallet private key or recovery phase, so you will know you wil be safe with yet another almost undestructable backup. So if you want to be really on the safe side with your sensitive backups of crypto wallet private keys or revocery phrases, then you should definetky check out Cryptosteel and Billfodl as an alternative to hardware crypto wallets for example and other more traditional ways of backing up sensitive data.
Billfodl is made from some of the highest quality marine grade 316 stainless steel according to the makers and that ensures that it is fireproof as essentially it is protected up to 1200C/2100F temperature and is top rated to protect against heat related elements that might destroy your sensitive data. Billfodl is also waterproof and protects against all water related threats, including corrosive salt water, so your data would be safe even at the bottom of the ocean floor. Billfodl is also shockproof. In fact it is apparently constructed to even withstand over a million volts of electricity, so whether it is solar spots, a nuclear strike, or a microwave bomb your backup should withstand it all.