Amazon.com recently unveiled prototypes of the drones it intends to use for its future delivery system known as Prime Air.

Prime Air, once approved by regulators, will get packages up to five pounds to Amazon customers in 30 minutes or less using small unmanned aerial vehicles.

“Prime Air has great potential to enhance the services we already provide to millions of customers by providing rapid parcel delivery that will also increase the overall safety and efficiency of the transportation system,” the company said, in a statement. “Putting Prime Air into service will take some time, but we will deploy when we have the regulatory support needed to realize our vision.”

Flying under 400 feet and weighing less than 55 pounds, Prime Air vehicles will take advantage of sophisticated sense-and-avoid technology, as well as automation, to operate to distances of 10 miles or more.

Amazon is testing several different vehicle designs and delivery mechanisms to discover how best to deliver packages in a variety of environments. “We have more than a dozen prototypes that we’ve developed in our research and development labs,” the company statement said. “The look and characteristics of the vehicles will evolve over time.”

Amazon Prime Air development centers are located in the United States, the United Kingdom, and Israel. The company is testing the vehicles in multiple international locations.

Amazon has published papers with its proposals for integrating Prime Air vehicles into the airspace. In a nutshell, Amazon is advocating that certain communication and navigation capabilities be required to gain access to certain airspace. Drone operators will allowed airspace access depending on the capabilities of their vehicles and where they intend to operate. Amazon advocates carving out “segregated blocks of airspace below 500 feet and away from most manned aviation operations.”