COMFORT YOU CAN COUNT ON Superfeet merinoGREY combine the natural, thermoregulating merino wool with Superfeet's legendary support and performance. The result is a supportive insole with a soft, felted merino wool top that will keep your feet warmer when it's chilly, and cooler when it's hot. So whether you're walking in the city or running a mountain trail, the comfortable support you feel will be with you all year long.