Amazon.com, Inc. (NASDAQ:AMZN) is expanding its Amazon Go checkout-free stores by opening them up in two new cities over the coming year.

Source: Amazon

Here are seven things to know about these stores:

• The experimental Amazon Go stores will now be available in Chicago and San Francisco, but the company did not reveal when they are opening.
• The e-commerce retailer said it is currently looking for retail space in the two cities to build its stores.
• There’s only one Amazon Go store at the moment in a small space located in the base of one of the company’s Seattle skyscrapers that opened to the public in January.
• The store uses a number of cameras and sensors to constantly track customers and inventory as they move around the store.
• In order to enter the store and shop, shoppers need to download the Amazon Go app, which will charge users for any products they take from their stores without them having to go through a checkout counter of any sort. The app automatically charges the items to users’ accounts.
• While there are no cashiers on these stores, there are plenty of human employees who are responsible for restocking shelves, checking ID for wines and working security.
• Since Amazon acquired Whole Foods last year, users can also grab their groceries at these stores.

AMZN stock is up 0.7% Wednesday.