For use with the Chrome browser in a recent version (38 or more). Enables secure access to a Google Account by enabling authentication in two stages, one of which is your password and the other is a randomly generated password to the request by this key (you must touch the part metal in the center. So even if your password is easy to remember (and thus alas, to guess), your account is secure because no one can access it without the key. The key works perfectly, is more robust than the other market economical solution for a price that is reasonable. The whole is relatively simple to configure on the Google site. Highly other market participants begin to use this solution!