https://www.theverge.com/2018/7/25/17613332/google-titan-security-key-login-2fa

Today at the Next conference, Google announced a new product called the Titan Security Key, currently available to Cloud customers and scheduled for general sale in the coming months. The key is used to authenticate logins over Bluetooth and USB, similar to existing offerings from Yubico and other providers. A Google representative said the Titan key also includes special firmware developed by Google to verify its authenticity.

“Titan Security Key gives you even more peace of mind that your accounts are protected, with assurance from Google of the integrity of the physical key,” Google said in a post announcing the key.