Amazon is upgrading its smart shopping carts that let customers skip checkout lines in some of the company's physical stores and is also making the carts available in more locations.

The Dash Cart, introduced in 2020, automatically keeps a real-time receipt of all the products shoppers put in them from store shelves (or take out). They're intended to speed up the amount of time it takes customers to get in and out of stores, using cameras near the cart's handlebar to scan items.

On Monday, Dilip Kumar, Amazon’s vice president of physical retail and technology said at Fortune’s Brainstorm Tech conference in Aspen, Colo., that his company would introduce carts that are weather resistant so that customers can take the carts straight from the store to their cars. The old version of the Dash Cart had to stay inside the store and customers had to carry their items to their cars.

When checking out, instead of standing in line to pay or unloading and reloading their items at a self-checkout kiosk, customers can leave the store through the Dash Cart lane and the credit card associated with their Amazon account will be automatically charged for the items they selected.

Amazon also plans to double the capacity of the carts so that that they can hold four shopping bags instead of just two.

The Dash Cart can also weigh fruits and vegetables, but shoppers must enter the type of produce they're buying in Dash Cart’s touch screen. Although the previous version of the Dash Cart required customers to enter a clunky PLU code for individual produce, the upgraded cart's screen will show shoppers which fruits and vegetables are nearby so as to make it easier to select them. Customers can also search for specific items by name.

To use the cart, customers sign into their Amazon accounts on the cart’s touch screen with a QR code and begin shopping. After grabbing an item off the shelf, and putting them in their cart, they can walk out of the store with them.

Dash Cart is already available in many Amazon Fresh stores. On Monday, Kumar said the carts will be available at Whole Foods Market in Westford, Mass. in the coming months, and more Amazon Fresh stores and some additional Whole Foods stores in the future.

Additionally, Kumar also said that three new stores will open in the fall at Texas A&M’s Kyle Field that use Amazon checkout-free technology.

After entering the stores, customers will be able to insert their credit card at the entry gate or pay with their palm using the Amazon One palm scanner. After grabbing snacks like chips, along with soda, bottled water, and alcoholic beverages, customers will be able to walk out without going through a checkout line while their credit card is automatically charged for the items they chose.

The new stores mark the first time Amazon’s checkout-free tech will be used at a college stadium, in this case, among the biggest, with a capacity for more than 100,000 spectators.

This story was originally featured on Fortune.com