A quick primer: Nike's Zoom Vaporfly 4% derives its name from its speed. Specifically, the shoe can make runners up to four percent more efficient than the Swoosh's previous fastest marathon shoe. It achieves the feat with two main features, spanning a Nike ZoomX midsole for responsive cushioning and a full-length carbon plate, designed to minimize energy loss during the toe bend without increasing demand on the calf. The Nike Zoom Vaporfly 4% finally drops this week, pictured here in an introductory Blue Fox/Bright Crimson/University Red/Black colorway. It's available July 20th at select retailers, Nike+ and nike.com.

Release Date: 7/20/17 (Thursday)