; The Prio fits true to size. Whether you're out on a run, trying out a new trail, hitting the gym, or toeing a slackline, you'll love the combination of freedom and protection from the Xero Shoes Prio. Life-changing comfort and superior performance come from using your feet naturally. Low-to-the-ground for balance and agility. Made from 100% vegan-friendly materials. Breathable mesh upper with a huarache-inspired tensioning system. Anatomically wide toe box for power-producing movement. Huarache sandal-inspired reflective heel and instep straps hold your foot securely - with or without socks - while keeping your toes free to move. Optional 2mm insole lets you have more or less of a barefoot feel depending on your mood. Dual-direction chevron tread provides stability and ground-gripping confidence. 5.5mm FeelTrue rubber sole. Polyester upper. Synthetic lining and insole. Rubber outsole. Imported.