Vivobarefoot Primus 3.5 FG Running Shoe – Men's size-10 6 oz (size US 9)

6 oz (size US 9) — one of the lightest options we carry for competitive XC racing

warm enough for a cold bivvy

while a wider base keeps your transitions smooth and stable

8 oz (236 mL) capacity — right-sized for snacks

no bunching mid-hike

Vivobarefoot Primus 3.5 FG Running Shoe – Men's size-10 6 oz (size US 9)Built for runners who want real ground feel on technical terrain, the Primus Trail 3. 5 FG is our pick for athletes transitioning to or training in barefoot footwear. A firm ground outsole with aggressive lugs delivers traction on dirt, roots, and rock, while the wide toe box lets your foot splay and work naturally. Zero drop, minimal stack height puts you in direct contact with the trail for honest proprioceptive feedback Firm ground (FG) outsole