Using the upper from the Nike Flyknit Racer, the Nike Flyknit Performance Track Spike is the latest in the Flyknit line. The spikes are engineered with top-of-the-line advances to increase speed, comfort, and support. The featherweight runner tips the scale at just 3.9 ounces thanks to its seamless design. This a distance track spike, and you can expect to see it on US 10,000 meter runner Dathan Ritzenheim. [via Nike, Inc.]