From Nike: The Nike Zoom Fly Women’s Running Shoe is made with Dynamic Support technology and springy, responsive cushioning composed of Phylon and Cushlon foams for an ultra-smooth ride. Flex grooves create natural range of motion while lightweight sandwich mesh on top gives you the best in breathability.
The Nike Zoom Fly is a great lightweight structured shoe. I started wearing this shoe after coming back from a foot injury. The shoe was recommended to me by my sports pt because it has a stiff, structured outside portion which stabilizes your 5th metatarsal and cuboid. The shoe has a narrow feel without a lot of bulk. It is a good shoe for the roads and trails, short runs and long runs as well. It is a nice all-around shoe.