The Seamless Top has been designed to have high breathability areas based on thermal imaging of trail runners in hard exercise in cold conditions. It is important to try to keep the skin dry and move perspiration away as efficiently as possible. The Seamless Top does this with it's blended fibres and variable tension knitting.
High stretch, unrestricted movement, skin fit, soft touch, high wicking. All these things make up a comfortable base layer to use in high activity in cold conditions
We know most runners only wear one layer most of the time, so even though this is a base layer, we put a pocket on the back for storage. If it is very cold (arctic) then it is a good place to keep some things from freezing.