Everyone needs a mid-layer that can be worn alone or under a jacket or vest, providing protection against cold winds during chilly runs. The Run Easy Warm Long Sleeve Mid Layer is designed for athletic use and features helpful details such as a honeycomb-structured fleece interior and thumbholes in the sleeve cuffs. By the way, this mid-layer is a favorite among our employees! It's a versatile, warm, and stylish mid-layer that gives you the necessary energy on your way to the next milestone.