Create your bitcoin key without electronics or microchips for unparalleled security. No operating system means your private key information is safe from hackers and malware.Randomly assembling 256 bits into the eight slots converts real-world entropy into a number that cannot be duplicated.
You basically insert metal pieces representing 1s and 0s into the cylinder shaped thing's slots. Then they have spreadsheets for generating seeds/public keys:
Create public keys and receive addresses via any offline and secure tool, including this website's free example spreadsheets, without exposing your key to internet-connected devices.
Definitely a bit whacky but pretty fun.