The running sock for understated comfort. Perfect for warm days and race days. Your new secret weapon Fit in focus - The pattern at the arch triggers sensory receptors to prime your feet for the run while Swiss engineering keeps the sock firmly in place. Expect improved fit and improved quality for performance standards that don't slip. Weather win - Made with 95% recycled polyamide and technical mesh paneling that balances temperature: cooling when things heat up, warm enough that you won't get cold feet. The ideal sock for whatever you're about to take on. Support when you need it - In an improved ultralight minimalist design made using recycled materials, the new Performance Low Sock is anatomically shaped to hug the foot for gentle support | On Men's Performance Low Sock in Hail/Wash, Size: 42-43. Warm weather runs, supportive, adaptive Running, Road Running, Workout, Marathon, Competition, Track And Field. Performance Running | Polyamide