“HFS” may be short for “Happy Feet Shoes,” “Hyper Flexible Soles,” or possibly what you’ll exclaim when you try this 7.4 ounce (M9) true road runner, “H___ ___ ___!” Your feet will love the natural comfort of the wide toe box and zero-drop design. The tire-inspired tread keeps you sure-footed. The moisture-wicking lining and breathable engineered mesh help keep you cool. Hidden instep and mid-foot tensioners give you the security you need to go for that new personal best.