"Ledger Nano S is a secure Bitcoin hardware wallet. It connects to any computer through USB and embeds a built-in OLED display to double-check and confirm each transaction with a single tap on its buttons."
"Trezor is a hardware wallet providing a high level of security without sacrificing convenience. Unlike cold storage, Trezor is able to sign transactions while connected to an online device. That means spending bitcoins is secure even when using a compromised computer."