Most hardware wallets ask you to trust the vendor's account of what is inside the case. Foundation publishes the schematics. Combined with US assembly and a documented supply chain, that answers the supply-chain question more completely than any competitor.
The air gap and the interface
No USB data, no Bluetooth, no Wi-Fi — transactions move by QR code through the camera and screen or by microSD. The interface is deliberately phone-like, with a keypad and a colour screen, which makes the air-gapped workflow bearable rather than punishing. Envoy, its companion app, handles account management and firmware updates.
What it costs you
Around $199, which is at the top of the range, for a device supporting one chain. If you hold anything besides Bitcoin you need a second device. Foundation is also a small company, so long-term firmware support carries more risk than it does with Trezor or Ledger.
Security specifics
A secure element stores the key, firmware is open and verifiable, and the device supports passphrases and multisig with Sparrow and other coordinators. There is no incident history.
Who should use it
Bitcoin holders who prioritise verifiability and supply-chain transparency, and who want an air-gapped device they will actually enjoy using. For multi-chain needs, look at Keystone.