Arc'teryx Rho Heavyweight Zip Neck Men is a thermal shirt, the heaviest of the entire line of this brand. It can be considered both a shirt to be worn as thermal functional underwear but also as a summer micro fleece. The inside is comfortable, soft and comfortable brushed fleece. A Polartec Power Stretch Pro that is highly stretchable while the outer is smooth nylon for bundles to glide over your other layers. The collar is high to also protect the neck and there is also a deep zip to regulate the internal ventilation and make it easier to put on. You can use Rho both for everyday life on the coldest days and for aerobic activities in the mountains, from the most intense to the softest ones. Arc'teryx Rho Heavyweight Zip Neck Men's technical polar fleece