Your rides run the gauntlet from too warm to too cold, and you don't shy away from your bike because of a little drizzle. The Castelli Gregge 15 Sock is constructed of a merino wool blend that naturally regulates temperature and manages moisture--standing up to both perspiration and precipitation. The blend is soft and flexible, and it's constructed with a reinforced toe and heel for extra durability. A thicker footbed cushions your foot against the stiffness of your shoe and improves warmth retention to minimize chills.