Odlo Evolution Light Long sleeve Crew:
Odlo's Evolution Light range offers excellent levels of breathability. The Evolution Light LS Crew boasts a hgh level of stretch for total freedom of movement and can be worn either as a baselayer in cold temperatures or a stand alone top inwarmer temperatures
Top fits great, but bear in mind that the neckline is quite low (lower than a normal top). Have used the base layer for both aerobic exercise (running etc) as well as long multi day hikes and it performs great.