Rubber sole Wide to allow for healthy foot spread and natural stability, Thin to enable you to feel more and move skillfully, and flexible to build foot strength enable natural movement. The Active Sole offers the most sensory underfoot experience, providing ultimate grip and durability on hard surfaces in urban environments. The signature 4mm thin sole puts the minimum material between your feet and the ground. Lightweight and versatile, whether you're working in or working out, keep your natural connection. (Re)new and improved- remade with recycled materials that have reduced this impact this footwear has on the planet. Train hard while treading lightly on the planet. The Primus Lite III is our hero trainer and its minimalist design lets your feet move in the most natural way possible. Building strength for every run, walk and workout.