Budget hardware wallet with a twist - it uses QR codes for signing instead of USB/Bluetooth, making it completely air-gapped. Your keys literally never touch a connected device. Has its own mobile app for managing assets. The S1 starts at $49 which makes it the most accessible hardware wallet. Build quality isn't Ledger-level, but the security model is solid. Good first hardware wallet if you're not ready to drop $100+ on Ledger or Trezor.