There's an old adage for winter riding, and it's that sweat is death. Think about it: you're working hard, the blood is moving, and you're perspiring just as you would be in the summer. But when the temperatures are at or near freezing, that moisture buildup turns icy and shocks the system. The result? You're honestly running the risk of hypothermia. It's kind of scary, but our Merino Long Sleeve Tech Layer provides an efficient solution. The science behind it is pretty simple. The base layer is comprised of a blend of synthetic, hydrophobic VaporRize™ fibers and Merino wool yarns that are naturally hydrophilic, meaning that thye love pulling moisture away from the skin. And when they do this, our blend of fibers distributes it across a large surface area where it can be rapidly evaporated. So when you think about it, no moisture buildup means that you won't experience any clammy chills as a result of dramatic temperature swings, and your skin, jersey, and jacket are going to remain dry in order to leave you comfortable. This material also comes with the added benefit in that Merino actually insulates quite efficiently when it encounters moisture, so you'll remain consistently and evenly warm—regardless of your level of effort. Add to this a flawless long sleeve design and a construction that seamlessly interfaces with a jacket or long sleeve jersey, and you have your ticket to ride all winter long.