The new ISW is a power-packed running sock built for the trail and beyond. Constructed with Isolwool, the ISW utilizes merino wool and polypropylene to deliver superior moisture movement. A light cushion prevents blistering and enables prolonged performance in the harshest conditions. Wool naturally fights bacteria allowing the sock to remain clean and fresh. The ISW is designed to perform in hot or cold environments - and to excel on the trail.