Vivobarefoot Primus Trail FG 3.5 is a lightweight, all-terrain trail trainer designed for close-to-ground feel and reliable grip on technical trails. Key attributes: Insignia Blue | Mesh | Zero-drop barefoot platform | Firm Ground outsole with aggressive lugs | Breathable, water-resistant upper | Lightweight (281 g per single shoe, EU 42) | Lace-up closure | Ortholite PU foam insole | Flexible sole for ground feedback | Ankle-height silhouette | Wide toe box for natural toe splay | Textured arch for zonal grip | Rugged lugged outsole | Dimensions & fit: Zero-drop barefoot fit (0 mm heel-to-toe drop) | Low stack height — 3 mm heel, 3 mm forefoot | Designed for trail running and all-terrain use | Composition & care: Mesh upper | Breathable mesh lining | EVA midsole | Firm Ground rubber outsole | Ortholite PU foam insole