Upper: Evolved Flywire technology is incorporated into the lacing system and hugs the entire length of the foot with lightweight, customizable support. External heel clip engages upon heel strike for a snug fit with support. Air mesh padded tongue maximizes ventilation and comfort. Plush padded heel collar for step in comfort that conforms to your heel.

Midsole: Lunarlon cushioning system with a "bottomless" carrier construction and the Dynamic Support platform provides adaptive support and plush cushioning. Dynamic Support provides stability for runners ranging from moderate overpronators to underpronators. Removable premium 3-layer sockliner for comfort and support. Nike+ ready.

Outsole: Natural motion engineered flex grooves promote a naturally efficient stride. BRS1000 in the heel for increased durability with an environmentally preferred compound in the forefoot.

"For such a lightweight shoe, the LunarGlide features excellent cushioning and stability, yet remains very flexible. That's a tough combination to execute well. The previous version of the LunarGlide struggled with this combination, garnering some of the lowest wear-test scores we've ever recorded for fit, comfort, and ride. This update was greatly improved. 'The perfect balance of springy yet pillowy cushioning, while having ample stability and support,' says Joe Kennedy, 32, of New York City, who has run in the LunarGlide+ 3. In RW Shoe Lab testing, all measures are better—the LunarGlide+ 4 is lighter by .7 ounces, lower to the ground, more flexible, and offers better cushioning and stability. The upper hugs the midfoot, thanks to a Flywire saddle, which provides a direct connection between the laces and the midsole to securely lock the foot in place. "