The last update to Google Wallet changed the focus and purpose of the app, and expanded compatibility to all phones, even iPhones, making it much more of an actual Wallet, including loyalty cards and offers, but the real focus is on being a PayPal competitor when it comes to how you transfer money and basically being an online bank.
And now Google is offering an official Google Wallet debit card. As you might expect, the card will work just like any other debit card and let you pay for items everywhere Mastercard is accepted. The Google Wallet card is backed by The Bankcorp Bank, and it can only draw money from your Google Wallet account balance. However, the card cannot be used like the NFC payments which use other linked debit cards and credit cards. You can also use the card to get money at ATMs using the same PIN that you would use in the app on your phone. It should be very convenient for users.
Not everyone will use the Google Wallet card. The people who will likely use it are sellers who use Wallet to accept payments, like developers in the Play Store for instance. Or those who use Google Wallet to send and receive money in general and happen to have a balance in their Wallet account. To get a Google Wallet card, just login to the Wallet website, and hit the “Wallet app and card” link.
Source Phone Arena