Vivobarefoot Primus Trail Knit FG Grounding Mens Wood Size:40eu wipe with a damp cloth wipe with a damp cloth and everyday adventures Upper Breathable mesh upper made from 100% recycled polyester Lining Lightweight breathable textile lining Insole No insole for enhanced ground feel and natural sensory feedback Closure Easy tongue construction with hook and loop fastening for independent on off Materials Vegan friendly construction using recycled materials Best Use Everyday play 5mm tread depth Midsole No traditional midsole for maximum flexibility and natural movement Outsole Firm Ground outsole with 3mm base and 2 A knit upper and sock bring flexibility and protection