The Sky long-sleeve (LS) shirt has been developed to quickly transports moisture through the fabric, away from the skin, spreading quickly over the outside of the fabric where it can more easily evaporate and/or be wicked away through the next layer, provided thats a functional layer, as well. in addition, the Sky shirt has been designed to look like you're wearing a casual garment when you take off your jacket. But make no mistake, this is a high-performance base layer: your first layer of defence against the elements. Features laminated reflective logo regular fit moisture wicking function