The Primus Lite is an extremely lightweight and flexible design. These shoes protect the soles of your feet but provide no support and do not guide your stride in any waythat is your body's job. Because the sole is very thin and flexible, your feet receive precise feedback about the surface and your movement. Note! The material blend used in the sole is spotty by nature. This is a feature, not a bug. - Total sole thickness: 3 mm - Flexible, soft, and highly grippy sole material - Upper material consists of mesh fabric and TPU Materials: - Upper fabric 1: recycled polyester - Upper fabric 2: 95% recycled polyester, 5% recycled Spandex elastane - Active Ortholite insoles: 98% recycled polyurethane, 2% water-based binder - Laces: recycled polyester - Lining fabric: recycled polyester - Outsole: 90% synthetic rubber, 10% natural rubber Transitioning to barefoot movement is a challenge for your body. Give yourself time to adjust to walking as nature intended! Start