NIKE Free Trainer 5.0 TB Men's Training Shoes - Navy/White Hexagonal flex grooves in the outsole allow your foot to move naturally for improved agility and exceptional range of motion. The anatomically shaped heel is rounded to roll with the ground, promoting greater control to help you stay fast on your feet. The Dynamic Fit system is anchored under the midfoot and adjustable through the laces for customized lockdown and a secure fit so you can focus on your workout, not on your feet. Breathable mesh upper for comfort