The SIXS Carbon Merino Underwear® long-sleeved st&-up collar shirt is breathable & thermoregulating in all weather conditions. The long sleeves completely envelop the arms, keep the skin fresh & lie between the skin & the underwear. At the same time, they easily protect against cold draughts when a short sleeve version is worn over the shirt. The contrasting st&-up collar also protects the neck from sudden changes in temperature & drafts. Features Seamless technology Antistatic system