Alphabet subsidiary Wing is pulling the curtain back on how it plans to cater to different industries that may come knocking on its door looking for on-demand drone delivery.

“We can have tiny planes for pharmaceutical delivery, big planes for shipping fulfillment, long-range aircraft for logistic flights, and dedicated hovering platforms for delivery in cities,” Adam Woodworth, Wing’s new CEO, explained in a blog post that talks about how the drone delivery company is building an “aircraft library.”

The key criteria for Wing’s aircraft remain the same: cargo should be about 25 percent of the plane’s mass. Moving away from that ratio means more cost, more energy, and more materials being expended to deliver a product.

“Cars, which perform most of today’s on-demand deliveries, are the ultimate example of this mismatch, where the stuff being carried represents less than 0.1 percent of the mass of the vehicle,” Woodworth points out.