Amazon has launched a new service that will deliver packages to the trunk of your car for free.

The Amazon Key app uses a camera and smart lock so Amazon prime members can have deliveries put inside their home or car. 

There are some restrictions on what can be delivered though. The company says nothing too heavy, big or expensive will be accepted. It also can’t be a delivery from a third-party. 

For now, the service is available in 37 cities, but the company hopes to expand to more areas soon.