Norrona Wool long sleeve T-Shirt is a merino wool first layer. Norrona Wool long sleeve T-Shirt is a merino wool first layer. It is made in Norrona's pureUll wool, a premium 100% merino quality and Norrona uses it because of the natural properties the wool offer: it is temperature-regulating, retains body heat while transporting moisture away, effectively keeping you warm, even when wet, and is also natural odor-resistant. The pureUll is an all-natural material made in 100% ultra-fine 18.5 wool micron that offers the perfect balance between performance and non-itching next-to-skin softness. It's a medium-weight (180gr/sqm) single jersey knit which is highly durable for its kind in terms of both wear and tear, pilling, abrasion, and snagging. The wool is RWS certified, and it's sewn and knitted in Europe. The fit is regular, and it has articulated arms for good mobility.